Major histocompatibility (MHC) class I–LILRB1/LILRB2 signaling axis: The expression of major histocompatibility complex class I (MHC I) on cancer cells hinders phagocytosis by interacting with the leukocyte immunoglobulin-like receptor (LILRB1) on macrophages [163]. Here, LILRB1 is linked to cancer.