The National Institutes of Health (NIH) has announced a funding opportunity titled "Research on the Neuro-Immune Axis in the Context of HIV and Substance Use (R21 Clinical Trial Not Allowed)." This grant aims to support exploratory research focused on identifying and characterizing neuroimmune networks and communication pathways related to HIV and substance use disorders, with an emphasis on discovering novel tools and mechanisms that could enhance understanding of these interactions. The initiative is particularly significant as it addresses the complex comorbidities associated with HIV and substance misuse, encouraging innovative scientific approaches with a funding ceiling of $275,000 over a two-year period. Interested applicants, including a diverse range of organizations and institutions, must submit their proposals by November 13, 2024, and can direct inquiries to grantsinfo@nih.gov for further information.