The present study is aimed at assessing the effect of simvastatin treatment on PON1 activity and its relationship to Q192R and M55L polymorphisms in subjects with stable coronary artery disease (CAD). Methods. The patient group was composed of 53 individuals with stable CAD, and the control group included 53 sex-matched police officers without CAD. The gene discussed is PON1; the disease is coronary artery disorder.