CD8A and neoplasm: Other predictive biomarkers, such as tumor-mutation burden, tumor-infiltrating lymphocytes (TILs) including CD8+ T cells and regulatory T cells (Tregs), neutrophil-to-lymphocyte ratio (NLR) in peripheral blood, and frequency of immune-suppressive cells in peripheral blood and tumor tissues have been evaluated to select patients who are more likely to respond to ICIs [7–12].