The effect of Nod2 deletion on HFD-induced obesity is strain-dependent, as Nod2−/− and WT C57BL/6 mice on HFD gain similar weight, but Nod2−/− C57BL/6 mice exhibit more severe insulin resistance21 than Nod2−/− BALB/c mice. Here, NOD2 is linked to obesity due to melanocortin 4 receptor deficiency.