Not surprisingly, HFD‐fed Park2 KO mice displayed improved glucose and insulin tolerance when compared with obese HFD‐fed wild‐type (WT) mice, but it was unclear whether changes in liver fat and glucose homeostasis after HFD feeding were due to loss of Park2 or secondary to the protection from obesity (Kim et al., 2011). Here, INS is linked to obesity due to melanocortin 4 receptor deficiency.