MAPK8 and obesity due to melanocortin 4 receptor deficiency: Although roles for JNK1 signalling in mediating insulin resistance through inhibition of insulin receptor signalling is well established in the periphery (Solinas and Becattini, 2017) and CNS (Belgardt et al., 2010), as yet there is limited direct data available examining the role of JNK signalling in glia in the context of obesity insulin resistance.