MAPK1 and Insulin resistance: Research has shown that in peripheral insulin resistance, processes such as synthesis and release of pro-inflammatory cytokines and activation of inflammatory stress signaling may cause phosphorylation of insulin substrate-1 (IRS-1) by kinase inhibitor of kappa B kinase (IKK), c-Jun N-terminal kinase and extracellular signal-regulated kinase 2 (ERK2), resulting in interference with insulin receptor-mediated signaling.