This analysis encompassed a total of nine cathepsins include cathepsin B, cathepsin E, cathepsin F, cathepsin G, cathepsin H, cathepsin L2, cathepsin O, cathepsin S, and cathepsin Z, and six digestive system tumors (HCC, PCa, BTC, CRC, GC, and EC). Here, CTSB is linked to colorectal carcinoma.