The best possible marker combination to discriminate BC from controls was the combination CFTR, SALL3, and TWIST1. We confirmed that these genes (and specifically CpG dinucleotides analyzed here) are hypermethylated in the bladder cancer tissue using methylation data from the TCGA Research Network [20] (Additional file 9: Figure S6). The gene discussed is CFTR; the disease is urinary bladder cancer.