The overall OR with its 95% CI revealed a statistical association between the PAI-1 promoter 4G/5G polymorphism and the risk of cancer (4G/4G vs. 5G/5G: OR=1.25, 95% CI=1.07–1.47, Pheterogeneity=0.001; 4G/4G vs. 4G/5G+5G/5G: OR=1.10, 95% CI=1.03–1.17, Pheterogeneity=0.194; 4G/4G+4G/5G vs. 5G/5G: OR=1.17, 95% CI=1.01–1.35, Pheterogeneity=0.041; Figs. 1 and 2). Here, SERPINE1 is linked to cancer.