CTLA4 and cancer: To evaluate the effects of MOF-gated MS in a prophylactic tumour model, (MS@OVAinMOF)@(anti-CTLA4inMOF) cancer vaccines, comprising the cancer model antigen (OVA) and anti-CTLA4 Ab, were fabricated to check the antitumour efficacy using E.G7-OVA lymphoma (Fig. 4; Supplementary Fig. 29).