CD8A and cancer: ccRCC tissues contain a variety of immune cells, including monocytes (M1 and M2 macrophages), lymphocyte (B cells, T cells and NK cells), and neutrophil etc. According to The Cancer Immune Atlas (TCIA, https://tcia.at/home) database, immunological composition analysis indicated that CD8 T cells gradually increase with ccRCC stages (stage I:7%; stage II:12.8%; stage III:13.4; stage IV:16.6%) (Figure 1E).