An immunodeficient mouse model that lacks mouse T, B and NK cells and that provides phagocytic tolerance (e.g., via SIRPANOD, human SIRPA transgene (SIRPATg), human SIRPA knock-in (SIRPAKI) or mouse CD47−/−) is necessary to prevent rejection of transplanted human immune and tumor cells [33]. The gene discussed is CD47; the disease is neoplasm.