Next, to demonstrate the role of local AngII in mediating the immune escape of tumor cells in BALB/c mice, the expression of AGT, a precursor of AngII, was stably silenced in 4T1 breast cells and CT26 colon cancer cells by lentiviral vector-mediated short hairpin RNA (shRNA), and the efficacy of the knockdown was shown in Additional file 1: Figure S1. The gene discussed is AGT; the disease is malignant colon neoplasm.