This pilot study showed a significant correlation between the CYP2A6 gene allele and the severity of coronary stenosis in univariable analysis (R = 0.24, P = .01); and persistently significant, even after adjustment for potential cardiovascular risk factors (i.e. hypertension, obesity, and dyslipidemia). Here, CYP2A6 is linked to obesity due to melanocortin 4 receptor deficiency.