Global DNA methylation alterations in UC. Supervised cluster analysis of 1,303 loci (784 genes) from bladder samples, using the Illumina GoldenGate methylation assay. N (n = 12) represents normal tissue from patients without urothelial cancer (UC); CN (n = 34) represents corresponding normal-appearing tissue from UC patients; Ta-T1 (n = 49) represents non-muscle-invasive bladder cancer; and T2-T4 (n = 38) represents muscle-invasive bladder cancer. No methylation is shown in blue, and increasing DNA methylation is shown in yellow. (a) UC-specific hypomethylated CpG sites, and (b) UC-specific hypermethylated CpG sites.