While this discrepancy may be partly explained by the older age of our study population (40 to 74 years vs ≥20 years in the Ausk et al report), it is also possible that fasting serum C‐peptide level is a more stable measure of insulin secretion and, therefore, produced more robust results across different stages of obesity than HOMA‐IR.9,13–14. The gene discussed is INS; the disease is obesity due to melanocortin 4 receptor deficiency.