We recently systematically reviewed the relationship among HSD11B1 abdominal adipose gene expression with obesity, T2DM and MetS in humans and reported that abdominal adipose HSD11B1 expression increased with increasing body mass index and abnormalities of glucose metabolism in most studies, but not in all, and varied with the presence of MetS. Here, HSD11B1 is linked to obesity due to melanocortin 4 receptor deficiency.