CD4 and colorectal carcinoma: The immune cells analyzed in CRC tissues included CD8+ T cells, CD4+ T cells, B cells, tumor-associated macrophages (TAMs), monocytes, M1 and M2 macrophages, neutrophils, and natural killer (NK) cells, dendritic cells (DCs), subsets of T cells [T helper 1 (Th1), Th2, follicular helper T (Tfh), Th17].