Fig. 5

PD‑L1 expression is correlated with p-ERK in patients with iCCA. A The expression levels of ERK, p-ERK and PD-L1 between tumor tissues and para-tumor tissues based upon IHC expression score. B p-ERK levels were positively correlated with the levels of PD-L1 protein based upon IHC expression score. Spearman r = 0.56. P < 0.0001. C ERK levels were not correlated with the levels of PD-L1 protein based upon IHC expression score. Spearman r = 0.0508. P = 0.6306. D Representative immunohistochemical staining of PD-L1, p-ERK and ERK in tumor tissues and para-tumor tissues of different patients. E The protein levels of ERK, p-ERK and PD-L1 were detected by western blotting analysis of cell lysates isolated from an additional 11 tumor tissues. GAPDH was used as loading control. F The relative protein expression (Normalized to GAPDH) of ERK, p-ERK and PD-L1 in iCCA tissues. Magnification, ×100. ***P < 0.001