Immunogen sequence: LDDNELIQFPC KIGQLINLRF LSAARNKLPF LPSEFRNLSL EYLDLFGNTF EQPKVLPVIK LQAPLTLLES SART Highest antigen sequence identity to the following orthologs - mouse 76%, rat 72%. May negatively regulate the 4-1BB-mediated signaling cascades which