Immunogen sequence: FHQLLCLLNS QIASVWHGTL SKLLGSLYAL GIPKASKELQ SVEQEVRWRM RKLKYKHLAF LAESCATLSQ EQHSQELLAE LLTHLERRWT EIEDSHTLVT VMMKVG. TBRG4 (transforming growth factor beta regulator 4), also known as CPR2 (cell cycle progression restoration protein