GRN and obesity due to melanocortin 4 receptor deficiency: We have reported that tumor necrosis factor (TNF)-related biomarkers, such as TNF receptors (TNFR1 and TNFR2) and progranulin (PGRN), are associated with the pathogenesis of obesity, diabetes, and CKD [14–16], and predict GFR loss and/or mortality in patients with diabetes and/or CKD [17–20].