The continuous decrease of TROP2 and EpCAM expression with grade in non-invasive urothelial bladder carcinomas in combination with the somewhat higher expression levels – to the degree of pTa G2 – in pT2-4 carcinomas could be explained by the unique evolution of pTa bladder cancers in vivo. The gene discussed is EPCAM; the disease is urinary bladder carcinoma.