SPP1 and cancer: For all cancers combined, the Mantel–Haenszel χ2 test with continuity correction had for OPN-a the test statistic χ2 = 11.688, p = 0.0006291, common odds ratio = 0.6955606 (95% confidence interval 0.5635650 to 0.8584717), for OPN-b the test statistic χ2 = 52.997, p = 3.34 × 10–13, common odds ratio = 0.4809881 (95% confidence interval 0.3920714 to 0.5900700), for OPN-c the test statistic χ2 = 188.16, p = 2.2 × 10–16, common odds ratio = 0.2618451 (95% confidence interval 0.2144581 to 0.3197027).