The finding that C8A mRNA predicts response to treatment with an HER2-targeting antibody that triggers an adaptive immune response and is highly prognostic strongly suggests that the C8A protein may provide a tumor survival advantage that, like PD-L1, suppresses the immune response.24 This also is supported by the GSEA analysis, which showed that a large number of immune-related gene sets are enriched in the C8A-positive tumors compared with the C8A-negative tumors in the HERA DASL cohort. This evidence concerns the gene CD274 and neoplasm.