Interestingly, when stratified by obesity status, rs7501939 at HNF1B only increased PCa risk in obese AAM (OR = 2.14, 95%CI = 1.2–3.8, P = 0.01) but not in the nonobese AAM (P = 0.76) or EAM of any BMI (P = 0.3 in obese, and P = 0.8 in nonobese EAM). Here, HNF1B is linked to obesity due to melanocortin 4 receptor deficiency.