Ffar1, also known as GPR40, is a G-protein-coupled receptor that functions as a receptor for medium-to long-chain free fatty acids [3,5]. It is involved in glucose-stimulated insulin secretion and incretin production, making it a potential therapeutic target for type 2 diabetes mellitus (T2DM) [1,2,4,6]. Activation of Ffar1 can enhance glucose-dependent insulin secretion without inducing hypoglycemia, and it is also implicated in processes such as inflammation regulation and secretion of peptide hormones [4,5].

In FFAR1 gene-deficient mice, stronger inflammatory and peripheral neuropathic pain-like behavior as well as depressive-like behavior were observed. The findings suggest that FFAR1 indirectly regulates dopamine release by promoting serotonin release, indicating its possible involvement in emotional behaviors [3].

In conclusion, Ffar1 plays a crucial role in glucose metabolism, with its activation being beneficial for T2DM treatment due to its glucose-lowering effect without hypoglycemic risk. The study of Ffar1 knockout mouse models reveals its significance in pain and emotional-related behaviors, providing insights into potential therapeutic applications for CNS disorders and chronic pain in addition to T2DM [3].