SIRPA and neoplasm: Antibodies to CD47 or SIRPα, developed against the TAM immunosuppression-related signaling pathway CD47-SIRPα (also known as the “don’t eat me” signal), allow macrophages to regain the ability to phagocytose tumor cells and restore the activity of CD8+ cytotoxic T cells, thereby significantly reducing tumor size and inhibiting tumor metastasis (14).