Immunogen sequence: EVRGETYLKG RGNETTYWLT GMKDQKFNLP TPPTVENQQR LQAEFSDMIA NSLQKRQAAG IRSQKPRRVA SYKKGTLEYL QLNTTD Highest antigen sequence identity to the following orthologs: Mouse - 79%, Rat - 80%. Receptor for the E.coli heat-stable enterotoxin (E.co