CTSL and hepatocellular carcinoma: As shown by immunohistochemical analysis, 35 of 82 (42.7%) paraffin-embedded HCC tissues showed weak or negative staining of CTSL protein, while 30 of 82 (36.6%) HCC tissues showed mainly moderate CTSL staining (in the membrane and cytoplasm of cancer cell) and 17 of 82 (20.7%) showed strong staining in tumor cells.