Indeed, M2 and Treg cells were markedly increased in the adipose tissues of huREG4IECtg mice, which were resistant to HFD-mediated obesity, whereas their levels were significantly decreased in Reg4 KO mice, which were more sensitive to HFD-mediated obesity (Fig. 1m and n). The gene discussed is REG4; the disease is obesity due to melanocortin 4 receptor deficiency.