SCFAs such as butyrate, propionate, and acetate signal through specific GPCRs, including GPR41 (FFAR3), GPR43 (FFAR2), and GPR109A, thereby modulating T cell function, inflammatory cytokine secretion, and tumor-associated signaling pathways, all of which contribute critically to breast cancer immunotherapy (Li et al., 2025). This evidence concerns the gene FFAR2 and breast cancer.