Secondly, past studies have proved that smoking, obesity, and chronic inflammation affect the production of cystatin C; all those factors were risk of CAD.[41–43] In our present study, a high serum level of cystatin C was associated with a high GS, suggesting that cystatin C had an active role in the biological process leading to format atherosclerotic plaque. The gene discussed is CST3; the disease is obesity due to melanocortin 4 receptor deficiency.