CD163 and neoplasm: PD-L1 expression on tumor cells was strongly correlated with the infiltration of CD163+ macrophages (r = 0.8582, p < 0.0001, Fig. 2C), and PD-L1 expression on interstitial cells was moderately related to the infiltration of CD163+ macrophages (r = 0.4232, p < 0.0001, Fig. 2D).