CD4 and obesity due to melanocortin 4 receptor deficiency: A previous study demonstrated a reduction of the circulating Treg cells in obese subjects and inversely correlated with inflammatory biomarkers, leptin, and BMI.32 Moreover, a recent study demonstrated a marked reduction of Treg lymphocytes, while CD4+ TEM cells increased in patients with morbid obesity.33 Children with metabolic syndrome demonstrated decreased Treg lymphocytes in the peripheral circulation.34 The data presented from the previous studies proposed that Treg cells play a significant function in suppressing obesity-related inflammation.