In addition, there was increased TYK2 promoter variant rate at statistical significance only in non-obese T2D with less than 26 BMI (OR, 2.4; 95% CI, 1.2 to 4.8; P = 0.01), but not obese T2D with more than 26 BMI (OR, 0.8; 95% CI, 0.2 to 3.7; P = 1.0) (Supplementary Table 4), suggesting that obesity is not likely involved in the increased risk associated with TYK2 promoter variant in T2D. Here, TYK2 is linked to obesity due to melanocortin 4 receptor deficiency.