EGFR and colorectal carcinoma: Furthermore, due to the strong inhibition of anti-tumor T cell responses via binding of tumor cell-expressed PD-L1 to T cell expressed PD-1 [51,52], decreased PD-1 expression on circulating splenic T cells in combination with decreased colonic PD-L1 expression in the present study may result in improved anti-tumor T cell responses in CRC mice treated either with a GFHPD or with an anti-EGFR antibody.