CD274 and cholangiocarcinoma: CCA subtype specific analysis for PD-L1 expression in association with patient survival showed decreased overall survival rates in iCCA patients with PD-L1 positivity in > 5% of tumor cells (p = 0.02, Fig. 3b) and decreased overall survival rates by trend in pCCA patients with PD-L1 positivity in > 5% of tumor cells (p = 0.06, Fig. 3d).