Immunogen sequence: PRAQLLIEER DTMETIDDRS TVLLTDADFG EAAKQKSLTV THTVHYQSVS QATGPLVDVS DARPGTNPTT RRNAKAGPTA RNRYASQWTL NRPHPTISAH TLTTDWRLPT PRAAGSVDKE SDSYSVSPSQ DTDRARSS. This gene is a member of the immunoglobulin superfamily of cell adhesion molecule