DDIT4 and obesity due to melanocortin 4 receptor deficiency: Increased REDD1 expression is involved in the pathogenesis of several metabolic disorders, including obesity and type 2 diabetes (T2D)6,7,9, macular degeneration, diabetic retinopathy10,11, muscle atrophy4,5, and hepatic steatosis6,7, as well as other pathogenic processes, such as neurodegeneration12,13, emphysema14, tumorigenesis15–17, and tumor angiogenesis8,18.