In contrast, as LTB4-LTB4R1 can induce 307 serine phosphorylation of IRS-1 in obesity, which in turn interferes in the insulin signaling pathway, the same authors also assessed the effects of the inhibition of serine kinases IKK, ERK and JNK. The gene discussed is MAPK8; the disease is obesity due to melanocortin 4 receptor deficiency.