A recent study demonstrated that the use of the immune checkpoint inhibitors, combined nivolumab, and ipilimumab, had intracranial clinical benefit for 57% of patients with metastatic melanoma.104 While pembrolizumab demonstrates activity in NSCLC BM with increased PD-L1 expression.105 In addition to research on the treatment of BM, there has also been recent interest in the prevention of BM, with a recent clinical trial demonstrating that temozolomide, in addition to T-DM1 for HER2+ breast cancer, has the potential for BM prevention.106. Here, CD274 is linked to breast cancer.