Preclinical studies have shown that PD-L1 blockade improves the immune response by restoring T-cell effectors functions. Recent work in two in vivo tumor models shows a strong interest in using an anti-PD-L1 in combination with standard treatment of colo-rectal cancer (FOLFOX). In these models, the survival of mice that are treated with the combination therapy reached 40% when no mice were alive with FOLFOX treatment alone. This result may be explained, in one hand by cytotoxicity of 5FU and in the other hand by the restoration of anti-tumor immune activity of anti-PD-L1. These results suggest that the combination of chemotherapy with immunotherapy would act synergistically in patients with colo-rectal cancer.