CD47 and cancer: Based on various cancer cell lines with or without expression of MHCI and CD47 as well as NSG mouse model of liver cancer, Barkal et al. confirmed that MHCI and CD47 are independent yet cooperative anti-phagocytic signals, and interference with MHCI/LILRB1 can enhance the phagocytosis of macrophages to tumor cells both in vitro and in vivo, which makes the signal axis an important regulator of innate immune cell response [25].