JAK2 and obesity due to melanocortin 4 receptor deficiency: To investigate the relationship between CHIP and obesity, we analyzed several mouse models harboring common CHIP mutations: Tet2, Dnmt3a, Asxl1, or Jak2 on the background of LepOb/Ob (Ob/Ob) mice to mimic the human pre-LHSCs/PCs condition occurring in individuals with obesity (24, 25).