IGHG3 and malignant colon neoplasm: As shown in Fig. 3a, b, human IgG2 anti-mCD40 antibodies significantly inhibited MC38 colon cancer cell growth in FcγR-humanized mice whereas IgG1 and IgG3 did not, consistent with our OVA-specific CD8+ T-cell response studies (Fig. 1b–d).