PON1 and metabolic syndrome: In the subgroup with dyslipidemia, we discovered that higher CpG4 levels of the PON1 promoter indicated a poorer clopidogrel response (cases versus controls (%): 51.500 ± 14.742 vs 43.308 ± 10.891, P = 0.036), and the PON1 mRNA expression was reduced in CR patients.