Recently, some discovered proteins such as geranylgeranyl diphosphate synthase (GGPPS), fatty acid translocase (FAT), protein tyrosine phosphatase-1B (PTP-1B), G-protein–coupled receptor kinase-2 (GRK2), adipose triglyceride lipase (ATGL), fibroblast growth factor 21 (FGF21) and peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) in mice adipocytes and muscle tissues that were found to be associated with the pathogenesis of insulin resistance. The gene discussed is FGF21; the disease is Insulin resistance.