Immunogen sequence: TGFEWNKYNQ THYDFDNPPP KIVQGYKFNI FYPDLIDKRS TPEYFLEACA DNKDFAILRF HAGPPYEDIA FKIVNREWEY SHRHGFRCQF ANGIFQLWFH Highest antigen sequence identity to the following orthologs: Mouse - 96%, Rat - 96%. Cactin is a novel negative regulator o