Complement C4a

C4a Complement; Complement 4a; Complement Component 4a; C4a, Complement; Complement, C4a; Component 4a, Complement
The smaller fragment formed when complement C4 is cleaved by COMPLEMENT C1S. It is an anaphylatoxin that causes symptoms of immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE) but its activity is weaker than that of COMPLEMENT C3A or COMPLEMENT C5A.