CD8A and cancer: We reviewed the details of infiltrating immune cells in each ICI cluster and found that anti-cancer immune cells, such as CD8 T cells, activated memory CD4 T cells and M1 macrophages, were elevated in ICI cluster A, and the volume of immune-regulating cell-like regulatory T cells (Tregs) was increased in ICI cluster C. These results partially explain the survival variations between the different ICI clusters and highly correlate with previous studies (8, 9, 26).