SIRPA and neoplasm: NI-1801 destroy mesothelin-positive solid tumors through the innate immune system; VEGFR1D2-SIRPαD1 consists of the second extracellular domain of VEGFR1 (VEGFR1D2) and the first extracellular domain of SIRPα (SIRPαD1), which exerted potent anti-tumor effects via suppressing VEGF-induced angiogenesis and activating macrophage-mediated phagocytosis (68–70).