CD4 and cancer: Furthermore, the Spearman correlation coefficient determined for the immune infiltration levels of B cells, CD8+ T cells, CD4+ T cells, macrophages, neutrophils, and dendritic cells were notably significant in 23, 23, 25, 23, 19, and 26 cancer types, which comprised a large proportion of the 32 cancer types interrogated (Supplementary Figures S1–S8).