Histopathological parameters are insufficient predictors for the individual course of disease in bladder cancer patients. In the past decade, however, other criteria have been developed as a possible prognostic aid to a better disease management, such as expression of specific cell surface antigens, DNA content, chromosomal aberrations, cell proliferation, tumor cell-associated antigens, angiogenesis, gene rearrangements, and point mutations. Since most tumors of the bladder are carcinomas and are associated with dedifferentiation and high metastatic capability, we investigated whether reduced expression of so-called differentiation factors in combination with increased cell motility might be correlated with tumor progression.