These fusion proteins, created by combining the CD47-binding domain of human SIRPα with either the human IgG1 or IgG4 Fc region, aim to enhance phagocytosis and anti-cancer activity of macrophages by blocking CD47-SIRPα contact between malignant cells and macrophages through Fc receptor engagement (9, 21, 52–55). The gene discussed is SIRPA; the disease is cancer.