To this aim, in this work, we have assayed the therapy with anti-CTLA-4 and anti-PD-L1, as well as with classical antitumor vaccines, on two growing murine tumors with widely different degrees of immunogenicity, a strongly immunogenic chemically-induced fibrosarcoma and a weakly immunogenic and highly metastatic mammary adenocarcinoma of spontaneous origin. This evidence concerns the gene CTLA4 and fibrosarcoma.