CD8A and breast cancer: We had previously found that treatment outcomes of olaparib in a mouse model of BRCA1-related BC depended on the TME: median survival was greatest when the tumor was implanted in syngeneic, immune-competent animals, significantly lowered when CD8 cells were depleted, and further decreased when the same tumor was treated as an allogeneic transplant in a SCID/beige host, suggesting that TME components beyond CD8 cells contribute to olaparib’s efficacy (Pantelidou et al., 2019).