At present, excluding studies with CellSearch system, detection of CTC in patients with bladder cancer is based on the expression of different epithelial markers at mRNA level in mononuclear cells isolated from 5 to 12 mL of peripheral venous blood, as reported for EGFR, CK-19 and CK-20 [46–51], and tumour-associated markers as MUC-7, Tenascin C, and Survivin [51, 52], with CTC positivity rates ranging from 10 to 80%, according to the type of marker and the stage of disease. The gene discussed is KRT19; the disease is urinary bladder cancer.