RIPK2 and obesity due to melanocortin 4 receptor deficiency: Nevertheless, considering the confounding example of body weight in the phenotype of Ask1 knockout mice and complexity of obesity-induced inflammatory response in vivo, we should keep in mind that negative regulation of the NOD-RIPK2 pathway by ASK1 in brown adipocytes may contribute to unidentified whole-body phenotype in some obesity-associated situation.