CD274 and neoplasm: The inverse association of PD-L1 alterations (amplification and polysomy) and residual disomy (Fig. 2A) pushed us to evaluate the correlation between residual PD-L1 disomy and the PD-L1 IHC immunostaining score, which was calculated as the percentage of the tumor cells with PD-L1 staining multiplied by its average intensity.