CD8A and cancer: As compared with that of wild-type cancer cell membrane-coated nanoparticles or single knock-in CD80- or OVA-nanoparticles, the double knock-in CD80/OVA-nanoparticles significantly induced cytokine secretion (i.e., IL-2 and IFN-γ) and increased the cytotoxicity of CD8+ T cells against target cancer cells, leading to inhibition of tumor growth in vivo.