CD274 and cholangiocarcinoma: In addition, IHC analysis in CCA patients demonstrated that although intratumoral CD8+ T cell infiltration did not correlate with PD-L1 expression in CCA cells, the higher ratio of CD8+ T cells to FOXp3+ T cells (suppressor T cells) was positively correlated with higher PD-L1 expression in tumor cells (r = 0.364, p-value = 0.001) (Fig. 7B).