FFAR3 and cancer: SCFAs regulate glycolipid metabolism and are substrates that bind to G protein-coupled receptors (GPRs), including GPR41 (i.e., free fatty acid receptor 3 [FFAR3]), GPR43 (i.e., free fatty acid receptor 2 [FFAR2]), and GPR109A (i.e., hydroxycarboxylic acid receptor 2 [HCA2]), which are associated with inflammation, immunity, and cancer.