Fatty acid-binding protein 4 (FABP4), abundantly produced by adipocytes, is released under lipolytic conditions and has been shown to enhance hepatic gluconeogenesis; in obesity and T2DM, circulating FABP4 levels are elevated, yet Mendelian randomization suggests no direct causal impact on insulin resistance [216,219,220]. The gene discussed is FABP4; the disease is type 2 diabetes mellitus.