CD8A and renal cell carcinoma: In contrast, CD4-CD8-T cell was a risk factor for RCC, with an OR value of 0.84 (95%CI = 0.71–0.99, P = 3.92 × 10–2), and the fact that CD4 + CD8 + T cell presented a protective effect against RCC also proved the above point (Fig. 2, Table 1, Supplementary Table 2).