It is involved in synaptogenesis and promotes synapse differentiation (PubMed:27812321). Suppresses neurite outgrowth (By similarity). Interacts (via LRR 1 and 2 repeats) with PTPRD (via extracellular domain). Expressed in the cerebral cortex of the brain and at higher levels in some astrocytic brain tumors such as astrocytomas, glioblastomas and primitive neuroectodermal tumors. Belongs to the SLITRK family.