MAPK8 and Insulin resistance: TNF-α and JNK contribute to insulin resistance by: i) promoting serine phosphorylation of IRS-1 and -2, ii) formation of a stable complex with IRS-1 and/or IRS-2, iii) impairing the ability of IRS-1 and -2 to associate with the insulin receptor and inhibiting insulin-stimulated tyrosine phosphorylation [54-57].