OR4D1 and obesity due to melanocortin 4 receptor deficiency: While the Chinese population showed smoking increased the risk of obesity for those with high olfactory receptor family 4 subfamily D member 1 (OR4D1) gene scores (OR = 2.67; 95% CI = 1.35, 5.30; P=0.005; Pinteraction = 0.041) but decreased the risk of obesity for those with high calmodulin-like 3 (CALML3) gene scores (OR = 0.25; 95% CI = 0.10, 0.62; P=0.003; Pinteraction = 0.026) after adjustment for age, sex, PA and alcohol consumption (41).