MMP9 and coronary artery disorder: Stratified by CT1, a subgroup analysis under allelic and additive genetic models found significant association between MMP-9-1562C>T gene polymorphism and CAD in both subgroups (allelic genetic model: subgroup 1: OR: 1.74, 95% CI: 1.28–2.36, P = 0.0004; subgroup 2: OR: 1.52, 95% CI: 1.10–2.11, P = 0.01) (additive genetic model: subgroup 1: OR: 1.89, 95% CI: 1.34–2.68, P = 0.0003; subgroup 2: OR: 1.72, 95% CI: 1.14–2.57, P = 0.009).