The classical and alternative complement pathways.<unk> is one of the proteins formed by the cleavage of complement component 3; the other is C3b.<unk> is a 77 residue anaphylatoxin that binds to the<unk> receptor <unk> , a class A G protein-coupled receptor. It plays a large role in the immune response.<unk> molecules induce responses through the GPCR<unk> receptor. Like other anaphylatoxins,<unk> is regulated by cleavage of its carboxy-terminal arginine, which results in a molecule with lowered inflammatory function<unk> desarginine).<unk> is an effector of the complement system with a range of functions including T cell activation and survival, angiogenesis stimulation, chemotaxis, mast cell degranulation, and macrophage activation. It has been shown to have both proinflammatory and anti-inflammatory responses, its activity able to counteract the proinflammatory effects of C5a.
C3a 
C1-inhibitor
Complement component 3
F-factor 
Complement component 4
Complement component 5a
Complement receptor 1
Ippa