CD8A and renal cell carcinoma: The infiltration abundance of immune cells was assessed by the CIBERSORT algorithm, and CD8 T cells were significantly different in the three renal cell carcinoma Clusters, with higher levels of immune infiltration for Cluster 2 than for Cluster 1 in KIRC and KIRP, and the highest level of immune infiltration for Cluster 1 in KICH (Fig. 2J-L).