2. Complement in clearance of apoptotic cell
The complement system is an important part of the innate immune system and play crucial role in apoptotic cell clearance. “Eate me” signals were expressed on apoptotic and necrotic cells surface, they attract the initiators of complement system such as C1q, mannose binding lectin (MBL), ficolins and trigger complement activation. C1q, MBL, and opsonins (C3b/C4b) are all participate in phagocytosis and clearance of apoptotic cells and necrotic debris. It is critical for development, regeneration, tissue remodeling, and homeostasis procedures24.