Immunogen sequence: CDKGYILVGQ AKLSCSYSHW SAPAPQCKAL CRKPELVNGR LSVDKDQYVE PENVTIQCDS GYGVVGPQSI TCSGNRTWYP EVPKCEWETP EGCEQVLTGK RLMQCLPNPE DVKMALEVYK LSLEIEQLEL QRDSARQST. There are 3 variants of Complement component 4 binding protein (C4bp), which is