In the 57 tissue specimens, 68.4% (39 of 57) of the specimens had a higher CypA immunoreactivity index in the tumor tissue when compared with respective adjacent normal bile duct lining cells; 26.3% (15 of 57) demonstrated equal degrees of staining; and, only 5.2% (3 of 57) showed weakly positive staining in normal bile ducts and lack of staining in tumor areas. This evidence concerns the gene PPIA and neoplasm.