In the current and our previous work, we provide in vitro evidence that exposure of adipocytes to OSM directly induces insulin resistance: OSM attenuated Akt phosphorylation induced by insulin [9], blunted the inhibitory action of insulin on FFA release, and induced phosphorylation of IRS-1 at Ser307 in 3T3-L1 adipocytes. This evidence concerns the gene IRS1 and Insulin resistance.