CD47 and B-cell non-Hodgkin lymphoma: Hu5F9-G4 is a humanized IgG4 isotype monoclonal antibody against CD47 and a macrophage immunological checkpoint inhibitor that blocks CD47 to induce phagocytosis; previous studies have found that Hu5F9-G4 may act synergistically with rituximab to eliminate B-cell NHL cells by enhancing macrophage-mediated antibody-dependent phagocytosis (62).