For instance, in breast, lung and colon cancer models, the FAP gene-engineered tumor-derived exosomes not only retain tumor antigen but also FAP antigen, which could induce CTLs against cancer cells and FAP+CAFs and reprogram immunosuppressive microenvironment by transforming TAM2 into TAM1 and reducing the infiltration of MDSCs. The gene discussed is FAP; the disease is cancer.