NOD2 and obesity due to melanocortin 4 receptor deficiency: Recently, it has been shown that Nod2 is required to maintain a normal microbiome in Balb/c mice when fed with a HFD and thus protecting them from obesity and metabolic syndrome since, Balb/c mice lacking Nod2 fed with a HFD gain weight and present glucose intolerance and IR similarly to C57BL/6 mice23.