Immunogen sequence: RQRSSRDPSW RQPERTILRP RFRREVEKTA CPSGKKAREI DESLIFYKKW ELEACVDAAL LATQMDRVNA IPFTYEQLDV LKHKLDELYP QGYPESVIQH. Originally identified as a differentiation antigen of mesotheliomas, ovarian cystadenocarcinomas, and pancreatic adenocarci