MMP2 and esophageal squamous cell carcinoma: For MMP2, a case-control study showed that patients with esophageal squamous cell carcinoma carrying the -1306CC or -735CC genotypes had an increased risk of developing cancer (odds ratio (OR) = 1.52, 95% confidence interval (CI) = 1.17–1.96; and OR = 1.30, 95% CI = 1.04–1.63 respectively).