MAPK3 and Insulin resistance: Several cell and animal studies showed that TNF-α promotes insulin resistance, inducing the activity of the mitogen-activated protein kinases (MAPKs) ERK1/2 and JNK [58], as well as the activity of the inhibitory kappa B kinase (IKKβ), PKC, mTORC1 and its downstream effector, ribosomal protein S6 kinase (S6K), which, in turn, phosphorylates IRS at Ser307, thereby determining the interruption of insulin signalling [59].