CD27 and biliary tract cancer: Furthermore, IVW analysis revealed positive correlations between biliary tract cancer and CD27 on CD20- CD38- (OR=1.14, 95% CI=1.02–1.28, P=0.0198), as well as IgD on IgD+ CD38- unsw mem (OR=1.12, 95% CI=1.03–1.23, P=0.01), IgD on IgD+ CD38br (OR=1.10, 95% CI=1.01–1.20, P=0.034), and IgD on IgD+ (OR=1.11, 95% CI=1.01–1.22, P=0.02).