ABCG1 and coronary artery disorder: There is statistically significant evidence to show that the ABCG1 gene promoter hypermethylation increases the risk of CHD in the total samples (OR = 22.859; 95% CI, 8.989–58.135; P<0.001 and OR = 19.966; 95% CI, 7.319–54.468; P*<0.001).