The molecules may provide additional diagnostic and prognostic information for cancer patients.1–3 In particular, increased activity, protein concentration and secretion of cathepsins B and L have been associated with poor patient outcome in various cancer types, including colorectal cancer (CRC).4 Other cysteine cathepsins, including Cat X have been studied far less in cancer and their role in malignant processes is not clear. The gene discussed is CTSB; the disease is cancer.