HNF4A and obesity due to melanocortin 4 receptor deficiency: Further, recent in vivo studies using human SHBG transgenic mice crossed with type-2 diabetic mice (C57BL/ksJ-db/db) have shown that hepatocyte nuclear factor 4 alpha (HNF-4α) and peroxisome proliferator-activated receptor gamma (PPARα) in liver are involved in obesity progression, while human SHBG overexpression partly prevents the increase in body and liver weight, as well as in the proportion of adipose tissue38, 39.