To further investigate the methylation and expression alterations of HIC1, SLIT2, RASAL1, and KRT17, massive bisulfite sequencing PCR and reverse transcription qPCR were performed in matched pairs of cancer and normal adjacent tissues from additional ∼33 bladder urothelial carcinoma patients (see methods for details). This evidence concerns the gene RASAL1 and bladder transitional cell carcinoma.