CTSL and digestive system neoplasm: Given the lack in the literature for a comparison of the tumor marker utility and possible prognostic relevance of cathepsins (CATB, CATL) and the uPA/PAI-1 system in the same experimental setting, in the current study, we surveyed the behavior of CATB, CATL, uPA, PAI-1 in CRC and compared with commonly used gastrointestinal tumor markers CEA and CA 19-9, and then evaluated any correlation between these parameters and the clinicopathological staging of CRC.