MC4R and type 2 diabetes mellitus: Interestingly, MC4R GoF variants were more strongly associated with a reduced risk of type 2 diabetes (OR [95% CI] per kg/m2 genetically lower BMI, 0.86 [0.85–0.87] for the 97-variant polygenic score versus 0.72 [0.62–0.83] for the β-arrestin-biased MC4R GoF variants, Pheterogeneity = 0.01).