As shown in figure 1A and online supplemental figure 1A, detectable levels of PD-L1 protein expression were observed in a proportion of cell lines derived from breast cancer, particularly of the triple-negative phenotype (MDA-MB-231—PD-L1high, HCC-1806—PD-L1moderate/low), ovarian cancer (OvCa3, MDAH), Hodgkin’s lymphoma (SUO-HD1, HDLM-2), or malignant melanoma (M257). Here, CD274 is linked to hepatocellular carcinoma.