Therefore, we analyzed PTEN copy number status by FISH on more than 2700 urothelial carcinomas in a tissue microarray (TMA) format and compared the results with histopathological parameters of disease progression in non‐muscle‐invasive and muscle‐invasive carcinomas and patient outcome as well as p16 and p53/TP53 status from a previous study in muscle‐invasive urothelial bladder carcinomas. The gene discussed is PTEN; the disease is urothelial carcinoma.