CD274 and breast cancer: Moreover, we screened five human cancer cell lines, colon adenocarcinoma (HCA-7 colony 29), breast cancer (MCF-7), glioma (U-87 MG), malignant melanoma (SK-MEL-28), pancreatic adenocarcinoma (MIA PaCa-2) to explore whether the acidosis- and IFN-γ-induced increase in PD-L1 expression represents a conserved tumor immune escape mechanism (Fig. 2I, S6A).