Studies were grouped according to the relationship they set out to assess: 1) HSD11B1 gene expression in subcutaneous/visceral abdominal fat and MetS [6-8]; 2) HSD11B1 gene expression in subcutaneous/visceral abdominal fat and hyperglycemia [6,8-14]; 3) HSD11B1 gene expression in subcutaneous/visceral abdominal fat and obesity [4,6-11,13,15-28]; 4) HSD11B1 polymorphisms and obesity, MetS, or T2DM [29-37]. The gene discussed is HSD11B1; the disease is obesity due to melanocortin 4 receptor deficiency.