CD8A and neoplasm: The efficacy of immunotherapy for CNS metastases may be enhanced by concurrent treatment with localised approaches such as stereotactic radiotherapy (which has overcome the resistance of melanoma to conventionally delivered radiation therapy 28) due to radiation-induced upregulation of major histocompatibility complex (MHC) class I molecules on tumour deposits making them visible to CD8 T-cells 29, and immunogenic cell death and priming of immune responses against tumour antigens 30.