IRS1 and Insulin resistance: F.H. Chen reduced insulin resistance via activation of the PPAR-γ pathway by directly increasing the expression of PPAR-γ2 and its responsive genes, adiponectin, IRS-1 and ap2, inhibiting TNF-α production and facilitating the translocation of GLUT4 to promote glucose uptake and disposal in 3T3-L1 adipocytes [24].