Epidemiologic Research on Emerging Risk Factors and Liver Cancer Susceptibility (R21 Clinical Trial Not Allowed) | PAR 22 084

Opportunity Information: Apply for PAR 22 084

The Epidemiologic Research on Emerging Risk Factors and Liver Cancer Susceptibility (R21 Clinical Trial Not Allowed) funding opportunity (PAR-22-084) is a National Institutes of Health (NIH) discretionary grant program designed to spur early-stage, innovative epidemiologic studies focused on liver cancer in the United States. Its central aim is to encourage researchers to test novel hypotheses about "emerging" risk factors for liver cancer, including biological, environmental, and social influences, and to examine how these newer or evolving risks interact with well-established drivers of liver cancer such as viral hepatitis. The program explicitly targets liver cancer broadly, including hepatocellular carcinoma as well as other histologic subtypes, signaling interest in research that can help explain differences in disease pathways, susceptibility, and population patterns across liver cancer types.

A key feature of the FOA is its emphasis on interplay: investigators are encouraged not only to identify new potential contributors to liver cancer risk, but also to evaluate how those contributors combine with established risk factors. In practical terms, that could mean studying whether certain environmental exposures amplify liver cancer risk among people with hepatitis infections, how metabolic or immune-related biomarkers may modify risk in the presence of known etiologies, or how social and structural conditions shape exposure patterns and downstream disease susceptibility. The intent is to move beyond single-factor explanations and toward more realistic models of causation that reflect how biological vulnerability and lived environment often intersect. Because the FOA is framed around "emerging" risk factors, it is well suited to timely questions tied to changing demographics, evolving exposure landscapes, and shifting clinical and public health conditions in the U.S.

This opportunity uses the NIH R21 mechanism, which is generally geared toward exploratory, developmental research that can generate preliminary data, establish feasibility, or open up promising new lines of inquiry. The "Clinical Trial Not Allowed" designation matters: projects that meet NIH's definition of a clinical trial are not permitted under this announcement. Applicants should therefore plan epidemiologic research that is observational or otherwise non-interventional in nature, such as analyses of existing cohorts, registries, linked administrative datasets, biospecimen-enabled population studies, or methodologically innovative epidemiologic approaches that do not assign participants to interventions or evaluate intervention effects. The overall focus remains on understanding risk, susceptibility, and etiologic pathways rather than testing clinical or behavioral interventions.

Eligibility is broad and includes many types of organizations that participate in health research. Eligible applicants span state, county, and local governments; special district governments; independent school districts; public and state-controlled institutions of higher education; private institutions of higher education; federally recognized Native American tribal governments; tribal organizations that are not federally recognized; public housing authorities and Indian housing authorities; and a wide range of nonprofit organizations (both with and without 501(c)(3) status). For-profit organizations other than small businesses, as well as small businesses, are also eligible, along with other entities that meet NIH requirements. The FOA also highlights additional eligible applicants and institution types, reflecting an interest in inclusive participation and research capacity across diverse settings. These include Alaska Native and Native Hawaiian Serving Institutions; Asian American Native American Pacific Islander Serving Institutions (AANAPISIs); Hispanic-serving Institutions; Historically Black Colleges and Universities (HBCUs); Tribally Controlled Colleges and Universities (TCCUs); faith-based or community-based organizations; eligible federal agencies; regional organizations; U.S. territories or possessions; Indian/Native American tribal governments other than federally recognized; and non-domestic (non-U.S.) entities, meaning foreign organizations can apply when aligned with NIH policy and the program's U.S.-focused scientific goals.

From an administrative standpoint, the opportunity is listed under Assistance Listing/CFDA number 93.393 and is categorized under the broad activity areas of education and health, consistent with NIH research support. The original closing date provided is May 7, 2025. The listing does not specify an award ceiling or the expected number of awards in the provided source text, so applicants would typically confirm budget parameters, anticipated award counts, and standard R21 constraints in the full FOA and related NIH guidance.

In summary, PAR-22-084 is essentially a call for creative, hypothesis-driven epidemiology aimed at clarifying why liver cancer develops and who is most susceptible, particularly as new biological insights, environmental realities, and social conditions continue to evolve. The NIH is looking for projects that can uncover or validate emerging risk factors and map their interactions with known causes like viral hepatitis, ultimately strengthening the evidence base needed to refine prevention strategies, risk stratification, and future research directions for liver cancer in the United States.

• The National Institutes of Health in the education, health sector is offering a public funding opportunity titled "Epidemiologic Research on Emerging Risk Factors and Liver Cancer Susceptibility (R21 Clinical Trial Not Allowed)" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 93.393.
• This funding opportunity was created on 2022-01-21.
• Applicants must submit their applications by 2025-05-07. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• Eligible applicants include: State governments, County governments, City or township governments, Special district governments, Independent school districts, Public and State controlled institutions of higher education, Native American tribal governments (Federally recognized), Public housing authorities/Indian housing authorities, Native American tribal organizations (other than Federally recognized tribal governments), Nonprofits having a 501 (c) (3) status with the IRS, other than institutions of higher education, Nonprofits that do not have a 501 (c) (3) status with the IRS, other than institutions of higher education, Private institutions of higher education, For-profit organizations other than small businesses, Small businesses, Others.

Apply for PAR 22 084

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