CD8A and melanoma: These results suggest that while the combination of RGS and anti-PD-1 did not result in an effective tumor growth inhibition of PDX-3101 established from an immune cold tumor in huNOG-EXL-PDX mice, these treatments were able to promote CD8+ T cell responses in the distant lymphoid organ and blood circulation, which is consistent with our previous findings in the syngeneic mouse models of melanoma [15].