MMP9 and coronary artery disorder: In contrast, Wu et al failed to find an association between MMP-9-1562C>T gene polymorphism and CAD in a Beijing population in 2009 (Wu et al., 2009) and Zhi et al observed no significant effects for MMP-9-1562C>T gene polymorphism on CAD risk in a Jiangsu population (Zhi et al., 2010).