The markedly higher rate of PLAP positivity and strong positivity in muscle-invasive (pT2-4) carcinomas as compared to pTa tumors in combination with the complete absence of PLAP staining in normal urothelium suggests that PLAP neo-expression occurs in a fraction of cases during development and progression of urothelial neoplasms. This evidence concerns the gene ALPP and urothelial neoplasm.