NOD2 and obesity due to melanocortin 4 receptor deficiency: Thus, our data demonstrate that Nod2 protects from lipid accumulation in the adipose tissue and liver, and that development of diet-dependent obesity in Nod2−/− HFD mice is associated with steatosis, formation of large LDs in hepatocytes, stressed adipocytes, and infiltration of macrophages in the adipose tissue.