C3 and neoplasm: We initially confirmed that peritoneal NK cells of CD11b−/− mice exhibited a more activated phenotype than that of WT mice (Figure S3 in Supplementary Material), and there was a large amount of deposition of activated C3 (C3b/iC3b) on tumor cells after 1 h of being injected into the peritoneal cavity (Figure S4 in Supplementary Material), indicating that sufficient ligands of CR3 can be generated rapidly.