CD8A and neoplasm: Immunophenotyping of peripheral blood mononuclear cells, isolated from 37 patients with omPCa (≤3 metastases) who were treated with metastasis-directed stereotactic body radiation therapy (SBRT) for all oligometastatic lesions, demonstrated that an increase in the number of tumor-reactive CD8+ T cells after intervention was associated with a diminished risk of disease progression in a study by Evans and co-workers [36].