Importantly, although the Fc-optimized V11(H1) anti-mCD40 antibodies significantly inhibited MC38 tumour growth in FcγR-humanized mice, V11(H3) displayed no antitumour activity (Fig. 3a, b), demonstrating that IgG3 CH1-hinge can deprive the V11 antibodies of their antitumour activities. This evidence concerns the gene FCGR2A and neoplasm.