SIRPA and neoplasm: IBI397 is a dual-mechanism inhibitor. Instead of directly blocking the binding of SIRPα to CD47, IBI397 blocks SIRPα-CD47 pathway signaling by mediating endocytosis of SIRPα on macrophages; in addition, the Fc-terminal end of IBI397 binds to the activated FcγR, which further enhances the tumor immunity and achieves the purpose of tumor suppression.