CD4 and cholangiocarcinoma: In addition, this study validated some equivocal conclusions made in the previously published studies [37] including: the negative prognostic values of Tregs and the Th1/Th2 ratio in all types of cholangiocarcinoma, the negative prognostic value of CD4+PD-1+ cells in DCC, and the negative prognostic value of CD8+PD-1+ cells in DCC and ICC.