Fusion protein amino acids 257-388 of mouse SynCAM1 (also known as synaptic cell adhesion molecule 1, immunoglobulin superfamily member 4, nectin-like protein 2 or NECL-2, tumor suppressor in lung cancer 1 or TSLC-1, spermatogenic immunoglobulin superfamily or SgIGSF, Igsf4 and Ra175, accession number Q8R5M8), recognizes 1.4b isoform only (epitope narrowed to GLTQLPNSAEELDSEDLS) Rat: 96% identity (129/134 amino acids identical) Human: 89% identity (118/132 amino acids identical) <50% identity with other SynCAM’s