Statement of Significance: Novel humanized mAb MM47 has excellent anti-tumor efficacy by blocking CD24/Siglec-10 interaction with strong antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis , antibody-dependent cellular trogocytosis and complement dependent cytotoxicity activities with a safe profile and has synergetic therapeutic efficacy when combining with programmed death-1 antibodies in cancer immunotherapy. Here, CD24 is linked to cancer.