ATP5F1B and obesity due to melanocortin 4 receptor deficiency: Recently, ATP synthase system (including ATP5b) and energy balance have been shown to be altered in several pathophysiological conditions such as muscles in obesity and diabetic patients20, acute kidney injury37, heart in pre-diabetic state38, reduction of DAPIT (diabetes-associated protein in insulin-sensitive tissue)39, human colon epithelial aging40, and hepatic ischemia/reperfusion injury41.