The algorithms of TIMER, EPIC, MCP-COUNTER, CIBERSORT, CIBERSORT-ABS, QUANTISEQ, XCELL, and TIDE were applied to explore the correlations among the infiltration level of immune cells, which include T cell CD8+ and CAFs using TCGA and APOE expression for different cancer types (Suppl. The gene discussed is CD8A; the disease is cancer.