CD8A and metastatic melanoma: reported that the PD-1+CD8+ TIL population recognized and killed autologous tumor cells compared with their negative controls in six tissues from patients with metastatic melanoma (MM), and the PD-1+CD8+ TIL population with specific TCRβ clonotypes contained clonotypes targeting mutant antigens and reserved the ability to recognize autologous tumor cells, showed highly monoclonal expansion.