LILRB1 and neoplasm: Blocking MHC-I or inhibiting LILRB1 either in vitro or in vivo enhanced phagocytosis of tumor cells by macrophages, and tumor cells expressing β2m prevented phagocytosis by macrophages and enabled evasion of the immune response.10 This suggests that the MHC-I-LILRB1 signaling axis functions as an antiphagocytic signal.