CD4+ Th1 cells may have similar contributions to obesity-related insulin resistance; reductions in adipose tissue Th1 by ablation of major histocompatibility complex (MHC) class II molecule (MHCII) on adipocytes or ATMs were associated with improved insulin resistance in obese mice (58, 68, 69). This evidence concerns the gene CD4 and obesity due to melanocortin 4 receptor deficiency.