The overall methylation levels of the 6 genes in NSCLC. Q-MSP assay was performed as described in Methods. The relative methylation level (on Y axis) is represented by ratios of candidate gene/β-actin (CALCA, CDH1, DAPK1, and RASSF1A × 1000; EVX2 and PAX6 × 100). Horizonal lines indicate a 95% confidence interval for the sample mean. T, tumor tissues; N, non-cancerous lung tissues. *, P < 0.05; **, P < 0.01; ***, P < 0.001.