CD4 and colonic neoplasm: More notably, correlations between the levels of immune cell infiltration of tumors in colon cancer and prognosis have been investigated in previous studies, which have shown that the degree of infiltration of various immune cells, including CD8+ T cells, is significantly associated with better prognosis, while the degree of infiltration of some CD4+ T cells (such as Th17 cells) is associated with poorer prognosis (33, 34).