CD4 and cancer: CCR8 antagonist may provide a much safer therapy for cancer relative to the anti-CCR8 ADCC strategy, the latter may cause severe side effects due to the expression of CCR8 not only on TI-Tregs but also on Th2 cells, Th17 cells, central memory CD4+ and CD8+ T cells, NKT cells, monocytes, vascular endothelial cells, and various normal tissues [14–17].