MAPK14 and obesity due to melanocortin 4 receptor deficiency: Recently, Hu et al. identified the first muscle-secreted lipid (named lipokine), 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLPC), which can induce the browning of WAT via lipid peroxidation-mediated p38 activation in male mice, thus significantly improving HFD-triggered obesity [308].