Immunogen sequence: MGANQLVVLN VYDMYWMNEY TSSIGIGVFH SGIEVYGREF AYGGHPYPFS GIFEISPGNA SELGETFKFK EAVVLGSTDF LEDDIEKIVE ELGKEYKGNA YHLMHKNCNH FSSALSEILC GKEIPRWINR LAYFSSCIPF LQSCLPKEWL TPAALQSSVS QELQDELEEA EDAAASASVA STAAGSRPGR HTKL. PNAS4 is a highly c