FDA Layoffs and Voucher Program Expiration Cast Shadow Over Rare Disease Drug Development

The FDA's Pediatric Priority Review Voucher (PRV) program has played a pivotal role in the fight against rare childhood diseases. Established to incentivize pharmaceutical companies to prioritize the development of treatments for uncommon pediatric conditions, the program has awarded priority review vouchers to companies that successfully bring new therapies to market. These vouchers can be used to expedite FDA review times for other drugs, providing a significant financial benefit and accelerating time‑to‑market for vital treatments. Despite its success, the program faced a significant setback when it expired in December 2024 due to Congress's failure to reauthorize it. This lapse has introduced a wave of uncertainty among drug developers and investors, which could potentially slow down the advent of new therapies targeted at rare pediatric conditions [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The expiration of the PRV program has far‑reaching implications. Economically, it removes a critical incentive for companies, especially smaller ones, that rely on the resale value of vouchers to fund ongoing and new research efforts. Without these incentives, the willingness of these companies to invest in challenging and costly drug development processes diminishes significantly. This is particularly troubling for rare diseases, where market sizes are small, and financial risks are disproportionately high [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/). Moreover, the increase in secondary market value of existing vouchers from $100 million in 2024 to $150 million in 2025 reflects an increased investor concern over whether future legislative support will indeed come [2](https://www.wsj.com/health/healthcare/drug‑development‑is‑slowing‑down‑after‑cuts‑at‑the‑fda‑f22369cf).

Socially, the expiration's impact is profound, primarily affecting children who suffer from rare diseases and their families. For these patients, any delay in the development of new treatments equates to a direct decline in their quality of life and potentially their lifespan. These children often suffer from conditions that are either life‑threatening or severely debilitating, necessitating urgent and effective treatments. The lack of available or forthcoming therapies can be devastating, leaving families and healthcare systems to cope with the resulting strain and emotional toll [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

Politically, the expiration of the program underscores a shift in legislative priorities and prompts a critical examination of governmental roles in supporting healthcare innovation. The debate centers on whether Congress and stakeholders will take action to reinstate the program swiftly. Advocacy groups are actively lobbying for the program's reauthorization, emphasizing its importance in fostering innovation and development in the rare disease space. Their efforts are bolstered by the realization that bureaucratic delays can stifle what little momentum exists for rare pediatric disease advancements [12](https://www.agencyiq.com/blog/legislators‑tee‑up‑renewed‑effort‑to‑pass‑rare‑pediatric‑drug‑bills/).

Ultimately, the absence of the PRV program, combined with recent FDA layoffs, presents a multifaceted challenge to the landscape of rare pediatric disease treatment. The combined forces of reduced government support and internal agency workforce cuts may lead to slower drug approvals and less robust support for pharmaceutical initiatives. This period of uncertainty has left many stakeholders anxiously awaiting news of potential legislative remedies or program reinstatements. Despite the uncertainty, there is cautious optimism that the importance of the PRV program will be recognized, leading to its eventual renewal and a renewed focus on rare disease therapies [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The Pediatric Priority Review Voucher (PPRV) Program has played a critical role in incentivizing the development of treatments for rare pediatric diseases. These conditions, often life‑threatening and complex, have historically seen limited attention from pharmaceutical developers due to the challenges inherent in conducting research within this population. Specifically, clinical trials involving children can be ethically and logistically complicated, requiring careful consideration and unique study designs. The voucher program offered a significant incentive by granting priority review status to developers who successfully produce treatments for these rare conditions. This acceleration in the review process can be pivotal, allowing companies quicker market access in competitive environments, subsequently enhancing the market viability of rare pediatric medications. Thus, the PPRV program serves not only as a catalyst for biomedical innovation but also as a critical component in the broader public health strategy aimed at addressing unmet medical needs in children.

Despite its success, the expiration of the Pediatric Priority Review Voucher Program brings significant concerns regarding future innovations in pediatric healthcare. Without the incentivization provided by the vouchers, smaller pharmaceutical companies, who often operate with limited resources, may find it financially daunting to embark on the lengthy and expensive process of developing drugs for rare childhood diseases. Consequently, the gap between the availability of necessary treatments and the needs of children with rare diseases may widen. According to Pharmaceutical Technology, the lapse in the program, compounded by recent FDA layoffs, further clouds the market, potentially deterring essential investments into this already challenging area of drug development.

The expiration of the program also raises broader questions about legislative priorities and the role of government in fostering innovative healthcare solutions. As noted in ongoing legislative discussions highlighted by,² efforts to reauthorize the program remain pivotal. Advocacy groups continue to press for its reauthorization, citing the program's effectiveness in encouraging the development of breakthrough therapies tailored to the specific needs of children suffering from rare conditions. These efforts reflect a deeper acknowledgment of the complex socio‑political environment influencing healthcare innovation and public health priorities. Until a clear legislative action is taken, uncertainty will persist, affecting not only the rare disease community but also the pharmaceutical landscape at large.

The expiration of the FDA's pediatric priority review voucher program has profound implications for the drug development sector, especially in the niche field of rare pediatric diseases. Historically, this program has been a vital mechanism, offering substantial financial incentives to pharmaceutical companies to engage in the challenging arena of researching and developing treatments for rare childhood illnesses. Such diseases often present significant hurdles in research due to the complexities involved in recruiting patients for clinical trials and the necessities of early diagnosis and intervention. With Congress's failure to reauthorize the program in December 2024, a pivotal source of motivation for companies, particularly smaller biotech firms, has been removed. This lapse introduces a level of uncertainty that can deter investment, as companies may be unwilling to embark on projects that lack the robust financial incentives previously afforded by the priority review vouchers [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The consequences of this program's expiration extend beyond just financial implications; they reach the core of drug development timelines and investor confidence. With the cessation of vouchers, we're likely to see a slowdown in the pipeline for new drug applications targeting rare pediatric conditions. This slowdown not only affects the market dynamics but also has far‑reaching effects on the availability of potentially life‑saving medications. Innovators in biotechnology and pharmaceutical sectors may reallocates resources to ventures with a more predictable return on investment, thereby involuntarily neglecting the urgent needs of rare disease sectors. This reallocation may stall the progress of pioneering research initiatives aimed at tackling some of the most challenging medical conditions affecting children [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

Compounding the issue of the voucher program's expiration are the concurrent layoffs at the FDA, which are likely to exacerbate the challenges of drug development. These layoffs are part of broader governmental downsizing efforts and threaten to diminish the speed and efficiency of the FDA's approval process. The reduced workforce is expected to delay drug approvals further, creating bottlenecks that could dramatically affect the ability of companies to bring new treatments to market. This scenario poses a significant risk not only to pharmaceutical companies but also to patients, particularly children with rare diseases who are dependent on timely access to innovative therapies. The dynamic between the program's expiration and FDA staffing reductions is set to create a complex barrier that must be navigated carefully to avoid long‑term setbacks in medical innovation [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The potential reinstatement of the FDA's pediatric priority review voucher program is a topic of considerable interest among industry stakeholders and investors. This program, which incentivized the development of treatments for rare childhood diseases, expired in December 2024. Its expiration has left many in the pharmaceutical industry concerned about the pace of innovation and investment in an already challenging field. However, there is optimism that Congress will eventually reauthorize the program, especially given its prior success in encouraging the development of critical therapies. The market’s reaction to this development has been significant. For instance, the value of existing priority review vouchers has surged, reflecting investor anxiety over the uncertain future of these incentives. The increase in voucher prices from $100 million to $150 million between 2024 and 2025 highlights the heightened demand and expectations for eventual legislative action to restore the program's benefits. This market trend underscores the critical role these vouchers play in balancing the risk‑reward equation for companies investing in rare pediatric disease initiatives. [FDA Layoffs and Priority Review Voucher Programmes Lapse Disrupt Rare Disease Pipeline](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The suspension of the priority review voucher program, coupled with FDA layoffs, poses significant challenges for both the pharmaceutical industry and investors. This dual predicament has understandably prompted cautious behavior among investors, who are now more vigilant about where to allocate their resources. There is a palpable sense of uncertainty that could potentially overshadow investor confidence unless the situation is addressed promptly. Legislative efforts are underway to push for the speedy reinstatement of the program, driven by advocacy groups and industry leaders who recognize its importance in promoting the development of novel treatments. Meanwhile, market reactions continue to reflect a cautious optimism. Investors hope for a resolution that reinstates the program's incentives, which are deemed vital for motivating companies to pioneer breakthroughs in rare disease treatment. Until then, the market will likely remain volatile, with stakeholders watching closely for any signs of political or legislative progress. [FDA Layoffs and Priority Review Voucher Programmes Lapse Disrupt Rare Disease Pipeline](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The FDA has recently faced significant challenges impacting its ability to approve new drugs efficiently. One of the primary concerns stems from the layoffs that have reduced the agency's workforce. These layoffs are part of a larger trend of government downsizing, which has hit the FDA particularly hard, given its critical role in public health. With fewer employees, the FDA is experiencing delays in processes essential for drug approval, including clinical trial evaluations and communications with pharmaceutical companies. These delays inevitably slow down the introduction of potentially life‑saving drugs to the market, a situation exacerbated by the expiration of the FDA's pediatric priority review voucher program. The program's lapse, which incentivized the development of treatments for rare childhood diseases, further compounds the risks posed by the FDA's diminished capacity [¹].

The impact of the FDA layoffs is multifaceted, contributing not only to the slowdown of drug approvals but also affecting the entire ecosystem of drug development. Pharmaceutical companies now face greater unpredictability as timelines for approvals become uncertain. This unpredictability can deter investment in new drug research, particularly for rare diseases that already carry higher risks and lower profit margins. Experts warn that without the FDA operating at full capacity, the innovation landscape in pharmaceuticals may suffer long‑term consequences. The interruption in drug approvals not only hinders economic growth in the biotech sector but also delays critical medical treatments needed by patients, who rely on timely innovation [³].

Furthermore, the layoffs and the pause in the priority review voucher program highlight a crucial gap in governmental support for rare disease drug development. Specialists in the field underscore how vulnerable populations, particularly children with rare diseases, are left in a precarious position. Without strong incentives for developing new treatments, these children face prolonged suffering and uncertainties about timely access to the latest medical advancements. The increased market value of existing review vouchers, which have risen noticeably, reflects the unease felt by investors and stakeholders about the current and future regulatory landscape. This situation underscores the urgent need for legislative action to reauthorize support for the FDA's programs that have proven effective in advancing medical innovation [⁴].

The expiration of the FDA's pediatric priority review voucher program marks a significant shift in the market dynamics of review vouchers, especially those tied to rare diseases. With the program's lapse, the once steady stream of incentives fostering rapid development in rare pediatric treatments has been disrupted. Previously, companies were motivated by the promise of expedited reviews, which allowed them to bring treatments to market more swiftly. Now, the absence of this program introduces a level of unpredictability that could deter investment in this niche yet crucial field. Reacting to this change, investors and pharmaceutical companies have become more cautious, fearing that the expedited pathways they once relied upon could vanish indefinitely. This has been reflected in the rising market value of remaining vouchers, highlighting how critical these tools are in the marketplace for rare disease treatment.

Moreover, the ripple effects of the program's expiration extend beyond simple market valuation. Investors are beginning to reassess their strategies, especially those involving partnerships and collaborations that heavily leaned on voucher‑enabled accelerated timelines. The increase from $100 million to $150 million in the market value of these vouchers in just a year underscores an urgent level of demand amid the dwindling supply. The surge captures the confidence that investors place in these vouchers as valuable assets despite the uncertainty clouding the program's reauthorization. It's a poignant reminder of the delicate balance between policy decisions and market confidence.

The legislative landscape too has been thrown into disarray, with lawmakers scrambling to introduce bills that would revive the priority review voucher program. The ongoing debates and legislative pushes reflect the broader apprehension within the pharmaceutical industry, emphasizing that the instability has created not merely financial anxiety but also a call to action to secure reliable paths for drug development. The thrust of these efforts lies in recreating certainty and reinstating incentives that, for years, propelled progress in fighting rare pediatric conditions. These developments indicate an industry on edge but ready to adapt should reauthorization materialize.

The opposition to the pediatric priority review voucher program largely stems from concerns regarding its scope and impact on pharmaceutical innovation. Critics argue that while the program was crafted with the noble intention of accelerating drug development for rare pediatric diseases, it has, at times, been exploited to expedite approvals for medications that do not specifically target rare conditions. This has led to a broader debate about how such incentives should be ideally structured to maximize benefits for the most vulnerable patients—children suffering from rare diseases (¹).

The broader implications of these criticisms extend into various facets of drug development and regulatory practices. By allowing vouchers to be used in non‑rare disease drug approvals, some fear that the focus could shift away from truly addressing unmet medical needs towards pursuing commercially viable yet less impactful developments. Advocacy groups and industry experts stress that while incentives are crucial, they must be carefully calibrated to prevent any dilution of purpose (¹).

The controversy surrounding the pediatric voucher program also highlights a critical tension between innovation and regulation. Proponents of a more restricted use of vouchers emphasize that without stringent guidelines, the risk of rendering such programs ineffective—by spreading efforts too thin across various drug categories—becomes significant. Conversely, those in favor of a broader application argue that it keeps the incentive structure alive, ensuring sustained interest from pharmaceutical developers even if the immediate outcomes are not tightly aligned with original objectives (¹).

Legislative efforts aimed at reauthorizing the pediatric priority review voucher program have gained momentum as stakeholders recognize the program's pivotal role in driving innovation for rare pediatric diseases. Urgency surrounds the reauthorization, with bills being reintroduced in the House of Representatives, aiming to extend the program's authorization until 2029. Advocacy groups are working tirelessly to ensure swift action, emphasizing that the program is crucial for maintaining the pace of development for life‑saving therapies. These efforts highlight a broad consensus about the program's importance and the need to avoid interruptions that hinder drug development for children with rare diseases. Continued advocacy and legislative action remain vital for instilling confidence in investors and supporting the pharmaceutical industry's commitment to addressing complex childhood conditions. For more information on legislative measures and advocacy efforts, you can refer to an [article on Pharmaceutical Technology](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The expiration of the pediatric priority review voucher program underscores the pressing need for legislative action in the field of rare disease drug development. By failing to reauthorize the program in a timely manner, Congress has inadvertently sown seeds of uncertainty among drug developers and investors. The resulting ambiguity threatens to slow down essential investments in innovative treatments for childhood diseases, potentially impacting the availability of new therapies. Legislative advocacy has become a rallying call for numerous stakeholders who are resolute in their efforts to avoid future disruptions. Efforts to reauthorize the program have galvanized bipartisan support in Congress, with stakeholders highlighting both the economic and humanitarian benefits of restoring the program. Learn more about the consequences of congressional inaction and the need for reauthorization in this comprehensive [article at Pharmaceutical Technology](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The expiration of the FDA's pediatric priority review voucher program has introduced significant financial uncertainty in the pharmaceutical industry. Designed to incentivize the development of treatments for rare pediatric diseases, the program offered companies the prospect of expedited FDA review through vouchers, which could be sold or transferred to other companies in need of quick review for their drugs. Without this program, smaller biotech companies face the daunting challenge of funding expensive and risky research without guaranteed financial incentives, potentially leading to a reduction in the number of new drugs entering the development pipeline. This absence of financial motivation poses a threat to the growth and innovation of pharmaceutical research, particularly for rare diseases that already suffer from limited attention due to their perceived lack of profitability. Moreover, the increased costs and financial risks associated with drug development in this area could deter many investors, who may now view the sector as less stable and more unpredictable. Consequently, the market might experience a slowdown in investment at a time when novel treatments are desperately needed.

Market uncertainty is further compounded by the recent layoffs within the FDA. Cuts in the workforce have the potential to delay the approval of new drugs, as the agency grapples with reduced manpower and resources. This can lead to longer waiting times for drug developers seeking approvals, thus elongating the time‑to‑market for new treatments. For investors, such delays introduce additional uncertainty, making pharmaceutical companies even more hesitant to invest heavily in the research and development of rare pediatric diseases. Without timely drug approvals, companies are less likely to receive quick returns on their investments, further perpetuating a cycle of financial hesitation and conservatism within the market. The lack of a clear timeline for approvals erodes investor confidence, which is reflected in the rising values of existing priority review vouchers on the secondary market. This increase signals a supply‑demand imbalance, with fewer vouchers available to expedite drug approval processes in an unpredictable market environment.

The expiration of the FDA's pediatric priority review voucher program has far‑reaching social impacts, particularly on patients with rare pediatric diseases and their families. This lapse in policy may lead to significant delays in the development of new treatments tailored to these vulnerable groups, causing profound distress and uncertainty. The lack of new therapies can drastically reduce the quality of life and life expectancy for affected children, as families find themselves navigating a healthcare landscape with fewer options and less support. The impact is not just medical but also emotional, as families grapple with the frustration of watching their loved ones suffer from conditions that could be alleviated with proper medical intervention. This situation underscores the urgent need for renewed commitment to incentivize pharmaceutical research and development that prioritizes these young patients.

Families affected by rare pediatric diseases are often left in a precarious position, forced to confront difficult decisions without the promise of new treatment options on the horizon. The reduced incentive for drug companies to invest in the development of new therapies means that parents and caregivers may face prolonged periods of caregiving responsibilities, associated emotional stress, and financial strain. This can exacerbate feelings of isolation and helplessness, as the hope for medical breakthroughs dims. Furthermore, the strain on caregivers often extends beyond the family, impacting workplaces, communities, and social services, as these support networks are stretched to accommodate the growing needs of these affected families.

Moreover, the social costs of this regulatory shortfall are vast and multifaceted. Without the development and approval of new drugs, rare diseases that might otherwise have effective treatments remain inadequately managed, leading to societal consequences that include increased healthcare expenses and burdened public health systems. The stress and emotional toll on families can result in diminished productivity, both in terms of workforce participation and societal contributions, as parents may need to reduce working hours or stop working entirely to care for their children. This ripple effect underscores the importance of comprehensive policies that support medical advancements and sustain economic and social supports for affected families.

The overall landscape for families and patients dealing with rare diseases is one of heightened anxiety and diminished capacity to cope with the challenges presented by these conditions. The expiration of the FDA's voucher program not only poses a threat to medical progress but also highlights broader societal issues, such as inequities in healthcare access and the persistent gap in resources for rare disease communities. These challenges demand a multi‑faceted approach that combines policy intervention, public awareness, and private sector engagement to ensure that families are not left to shoulder this burden alone.

The expiration of the FDA's pediatric priority review voucher program has thrown a spotlight on the legislative challenges and shifting priorities within the United States Congress. As the program that incentivized development for rare pediatric diseases lapses, it reflects broader trends in congressional focus. Debate about the reauthorization of this program highlights a tension between immediate fiscal concerns and long‑term health benefits, particularly as advocacy groups push Congress to act swiftly to reinstate it. The legislative gridlock, evidenced by the expiration, underscores the complicated nature of pharmaceutical legislation, where diverse interests must be balanced [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

Congress, in grappling with this issue, faces pressure from multiple stakeholders, including pharmaceutical companies, advocacy groups, and healthcare professionals who are advocating for the reauthorization. This process opens a broader discussion on how legislative bodies prioritize healthcare initiatives and the implications of these priorities for public health. The debate may also serve as a catalyst for reconsidering how incentives are structured to encourage development in underserved areas of medicine, potentially leading to more sustained and focused legislative efforts in the future [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

Furthermore, the political implications extend beyond healthcare policy. Lawmakers must contend with voter expectations and the necessity of maintaining a balanced budget. This environment of competing interests and limited resources makes the legislative landscape particularly challenging for maintaining programs like the pediatric voucher system. This context not only affects drug approval processes and related policies but also has the potential to redefine priorities in future congressional sessions. By navigating these complex political waters, lawmakers are essentially setting precedents for how rare disease treatments are developed and supported by government programs [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

Debate around the voucher program’s expiration is likely to influence FDA oversight and funding structures. It may prompt legislative scrutiny of the FDA's capacity and efficiency, driving reforms that could have lasting impacts on how drug approvals are managed. Lawmakers might also focus on the implications for economic competitiveness, given how integral pharmaceutical innovation is to the U.S. economy. This confluence of healthcare policy and economic strategy can inspire new debates and policies that not only aim to reach past the current impasse but also redefine the role of legislative support in pharmaceutical innovations [1](https://www.pharmaceutical‑technology.com/features/fda‑layoffs‑and‑priority‑review‑voucher‑programmes‑lapse‑disrupt‑rare‑disease‑pipeline/).

The expiration of the FDA's pediatric priority review voucher program, coupled with significant FDA layoffs, presents critical challenges to the future of rare pediatric disease treatment. The voucher program once offered a crucial incentive to pharmaceutical companies to invest in developing treatments for rare childhood diseases. However, with its expiration in December 2024, this motivating factor has been abruptly removed, leading to increased uncertainty within the industry. As noted by David Ridley, a health economist at Duke University's Fuqua School of Business, the absence of reliable incentives may deter necessary investments in this field, jeopardizing the pipeline of new treatments.

The economic implications are quite stark. Without the promise of the vouchers, smaller biotech firms, already operating with constrained resources, may opt out of researching rare pediatric diseases altogether. This withdrawal could slow the arrival of potentially life‑saving therapies for children suffering from these conditions. Moreover, the secondary market already reflects increased nervousness among investors, with voucher values spiking from $100 million in 2024 to $150 million in 2025, indicating heightened uncertainty and the pressing need for legislative action to mitigate these concerns.

Socially, the impact on affected children and their families cannot be understated. The lack of new medications could result in prolonged suffering and reduced life expectancy for young patients. Already strained healthcare systems may face further pressure as they attempt to manage these conditions without the necessary advancements in medical treatments.

Political dynamics surrounding the program's expiration are equally complex. Its lapse signifies a shift in congressional priorities, which some advocacy groups and stakeholders are working hard to reverse. They underline the program's past success in promoting pharmaceutical innovation and stress the need for reauthorization. Legislative efforts are underfoot, but until concrete steps are taken, the uncertainty continues to loom over the political landscape.

Consequently, the combination of an expired incentive program and the reductions in FDA staffing portends a period of difficulty for rare pediatric disease treatment development. Until resolved, the repercussions of these issues will likely stifle innovation and delay essential medical advancements, affecting both individuals directly and the broader healthcare landscape. There is hope that legislative efforts may eventually restore some stability, but the timeline for such intervention remains uncertain.