CTRB1 and colorectal carcinoma: Second, previous studies of CRC-related serine proteases have primarily focused on members of the trypsin family, whereas we detected higher levels of two trypsins (TRY2 and TRY4) and four chymotrypsin or chymotrypsin-like proteases (CELA1, CEL2A, chymopasin, and CTRB1) in the TIFs and sera of ApcMin/+mice.