It also can activate AMPK, and lead to changes in the expression of low-density lipoprotein receptor (LDLR), SREBPs and proprotein convertase subtilisin/kexin type 9 (PCSK9), thereby inhibiting obesity in C57BL/6J mice [35]. The gene discussed is PCSK9; the disease is obesity due to melanocortin 4 receptor deficiency.