The National Institutes of Health (NIH) is offering a funding opportunity titled "Mitochondrial-associated Mechanisms of Neuropathological and Immunodeficient Aging in the Context of HIV and SUD (R21 Clinical Trials Not Allowed)." This initiative aims to support exploratory research projects that investigate the intersection of mitochondrial function, aging, HIV infection, and substance use disorders (SUD), with the goal of informing targeted therapies to improve health outcomes for affected individuals. The total funding available for this opportunity is $3,000,000, with individual project budgets capped at $275,000 for a maximum duration of two years. Applications will be accepted starting February 10, 2025, with a submission deadline of March 10, 2026. For further inquiries, interested applicants can contact NIH Grants Information at grantsinfo@nih.gov or visit the additional information link at https://grants.nih.gov/grants/guide/rfa-files/RFA-DA-26-010.html.