APC and lung cancer: The ORs for APC methylation in cancer tissues compared with that in normal controls were 4.67 (95% CI: 2.66 to 8.22, z = 5.35, P < 0.0001) in random effects model pooled, and 2.74 (95% CI: 1.99 to 3.23, z = 8.10, P < 0.0001) in fixed effects model, demonstrating a statistically significant increasing in likelihood of methylation in lung cancer tissues comparing to controls (Figure 1).