Hong's study did not find the association between me‐NAM and HDL perhaps due to the severity of obese patients because serum me‐NAM levels were affected by obesity.5, 7 However, hepatic NNMT activity was inversely associated with HDL in an animal model in their study,21 which is consistent with our finding. The gene discussed is NNMT; the disease is obesity due to melanocortin 4 receptor deficiency.