Immunogen sequence: AEDDTNEEQT TFTNSQTSTE DPGDSTPFED SEEFCFSAEA NSFDGDDEFD TYNEDDEEDE SETGYWITCC PTCDVDINTW VPFYSTELNK PAMIYCSHGD GHWVHAQCMD LAERTLIHLS AGSNKYYCNE HVEIARALHT PQRVLPLKKP PMKSLRKKGS GKILTPAKKS FLRRLFD. RAG2 (V(D)J recombination-activating p