SERPINA4 and inflammatory bowel disease: They are known to be irreversible suicide inhibitors of proteases, but they can also participate in critical proteolytic pathways such as blood coagulation (SERPINA1, SERPINA5, SERPINA8, SERPINA10), tissue remodelling (SERPINA1, SERPINA3), angiogenesis (SERPINAC1), inflammation, apoptosis and tumour metastasis (SERPINA1, SERPINA3, SERPINA4, SERPINAC1).52, 53 High levels of SERPINA1 are associated with inflammatory bowel disease and CRC progression.54 These studies reinforce the notion that SERPINA1 is associated with tumour invasion and could be a useful protein marker for CRC diagnosis.