The National Institutes of Health (NIH) has announced a funding opportunity titled "Modulating Human Microbiome Function to Enhance Immune Responses Against Cancer" (R21 Clinical Trial Not Allowed), aimed at supporting exploratory research on the human microbiome's role in anti-tumor immune responses. This initiative seeks to elucidate mechanisms by which specific microbes or their metabolites can influence tumor immunity, with a focus on identifying novel molecular targets for cancer prevention strategies. The research is particularly relevant for understanding the gut microbiome's impact on cancer development and immune responses, especially in individuals with altered gut microbiota. Eligible applicants include various educational institutions, nonprofits, and government entities, with a funding ceiling of $275,000 available over a two-year period. Applications must be submitted by January 7, 2025, and inquiries can be directed to the NIH OER Webmaster at OERWebmaster03@od.nih.gov.