In particular, the expression level of FDX1 was well correlated with six types immune-related cellular infiltration (including CD8+ T cells, CD4+ T cells, dendritic cells, mast cells) in BRCA, six types (including T cells, monocytes, macrophages, mast cells) in renal cancer, five types (including CD8+ T cells, regulatory T cells, dendritic cells, mast cells) in THCA, and four types (including plasma cells, macrophages, dendritic cells) in TGCT. The gene discussed is CD4; the disease is renal carcinoma.