CD4 and cancer: After a series of analyses, we observed a significant statistical correlation between ACO2 expression and tumor immune cell infiltration, including B-cell infiltration in BRCA, COAD, and HNSC (Figure 8A), CD4+ cells in HNSC-HPV+ and LUAD (Figure 8B), CD8+ T cells in KIRP, LIHC, and LUAD (Figure 8C), and TANs in some cancers, especially COAD (Figure 8D).