CD4 and colonic neoplasm: Studies demonstrated that CCR5 enhances TGF-β–mediated killing of CD8 (+) T cells in colon cancer by recruiting Tregs (CD4 + FOXP3+) (Chang et al., 2012), and Blattner et al. reported that CCR5 induces the recruitment and homing of Tregs to the TME to stimulate immune evasion and tumor growth (Blattner et al., 2018).