CTLA4 and neoplasm: Preclinical study has shown that dual CTLA-4 and PD-L1 blockade inhibits tumor growth in the microsatellite stable highly aggressive orthotopic mouse model of colon cancer due to anti-tumorigenic T cell responses mediated by CTLA-4 inhibition and M1 macrophage polarization predominantly induced by PD-L1 blockade (9).