Is predicted to encode a protein with the following domains: Immunoglobulin I-set domain; Immunoglobulin I-set; Immunoglobulin subtype; Fibronectin type III; Immunoglobulin-like fold; CD80-like C2-set immunoglobulin domain; Immunoglobulin domain; CD80-like, immunoglobulin C2-set; Immunoglobulin subtype 2; Fibronectin type III domain; Immunoglobulin-like domain superfamily; and Fibronectin type III superfamily. Is an ortholog of C. elegans syg-2. In C. elegans, syg-2 is involved in cell-cell signaling; nervous system development; and protein localization to synapse.