CDH23 and esophageal squamous cell carcinoma: Next we correlated the extent of DNA methylation with mRNA expression for Cdh23 from the TCGA and noticed a negative correlation in both LUAD (Fig. 4C, n = 456, Spearman r = −0.36, 95% CI −0.43 to −0.27, P < 0.0001) and ESCC (Fig. 4C, n = 185, Spearman r = −0.46, 95% CI −0.57 to −0.33, P < 0.0001).