This Notice of Funding Opportunity (NOFO) issued by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) under the National Institutes of Health (NIH) invites applications for exploratory and developmental pilot research projects focusing on HIV-related pathogenesis, comorbidities, coinfections, and complications (CCCs) relevant to the NIDDK mission. The R21 mechanism supports innovative basic and translational research without the inclusion of clinical trials. Projects must align with NIH HIV/AIDS research priorities, as outlined in NOT-OD-20-018, and focus on biological, behavioral, or social mechanisms impacting CCCs, viral reservoirs, and social determinants of health (SDoH) within NIDDK’s scope.

Potential research areas include understanding HIV reservoirs in tissues such as the gastrointestinal mucosa, kidneys, and adipose tissue, as well as the impact of health-impeding SDoH like food insecurity, housing instability, and stigma on HIV-related health outcomes. Studies on the role of HIV or antiretroviral therapy in contributing to gastrointestinal, metabolic, liver, kidney, and urologic diseases, as well as the effects of HIV on the microbiome and mucosal immunity, are also encouraged. Applications involving non-NIDDK mission areas or those with a primary focus outside the scope of HIV/AIDS priorities will be deemed nonresponsive.

Eligible applicants include public and private higher education institutions, nonprofits, for-profit organizations, and government entities, among others. Foreign institutions are not eligible to apply. Applicants must be registered in the System for Award Management (SAM), Grants.gov, and eRA Commons, and individuals must possess the necessary expertise and resources to carry out the proposed research. Applications must be submitted electronically, with the earliest submission date on April 7, 2025, and a deadline on May 7, 2025, for the first cycle. The combined direct cost for two years may not exceed $275,000, with no more than $200,000 allowed in any single year.

Proposals should include a detailed research strategy describing how the project will contribute to larger-scale research efforts, such as R01 applications, and outline how results will advance HIV/AIDS-related knowledge within NIDDK's mission. The research plan must adhere to NIH’s Data Management and Sharing Policy and incorporate standard data elements whenever possible. Applications must demonstrate rigor, feasibility, and innovation while addressing NIH’s review criteria, which include the significance of the research, the quality of the approach, and the expertise of the investigators.

Awards are contingent on the availability of funds and the merit of the applications. Applications will undergo NIH’s peer review process, with funding decisions based on scientific merit, program priorities, and alignment with NIDDK’s mission. For inquiries about program scope, eligibility, or submission, applicants are encouraged to contact designated scientific, peer review, and grants management staff. Further details are available in the full announcement and related NIH guidelines.