CD33 and biliary tract cancer: Basophil %CD33dim HLA DR- CD66b- (OR=0.91, 95% CI=0.84–1.00, P=0.038) and CD33 on CD33br HLA DR+ (OR=0.95, 95% CI=0.90–1.00, P=0.04) from the myeloid lineage showed a negative correlation with biliary tract cancer risk, indicating an association with a decreased risk of biliary tract cancer (Figure 5).