FTO and obesity due to melanocortin 4 receptor deficiency: Studies mainly based on European populations have found that the methylation of ATP‐binding cassette G1 (ABCG1) gene, fat mass and obesity associated (FTO) gene, potassium voltage‐gated channel member 1 (KCNQ1) gene, and thioredoxin‐interacting protein (TXNIP) gene were associated with T2DM.15, 16, 17