CD4 and colorectal carcinoma: Furthermore, Tregs suppress the activation, proliferation and effector functions of CD4+ and CD8+ cells, NK cells, B cells, maturation of dendritic cells (DC) as well as inhibition of co-stimulatory molecules In addition to exerting immunosuppressive activity, infiltration of Tregs can initiate angiogenesis and increased vascularization leading to poor outcomes in CRC patients [43].