May form homotrimers or homodimers. Expressed in brain, heart and testis (at protein level). In the cerebellum, has particularly strong expression in Bergmann astroglial cells (at protein level). Detected in cortical plate, trigeminal ganglion, dorsal root ganglia and the spinal cord at embryonic stage 14.5 dpc. Widely expressed in brain at postnatal day 7 including cortex, olfactory bulb, hippocampus and cerebellum. Expressed throughout layers II-VI of the cortex. In the olfactory bulb, has strongest expression in glomerular and mitral cell layers. In hippocampus, localizes to CA1, CA2, CA3 and dentate gyrus regions. In cerebellum, mainly expressed in the internal granule cell layer and the Purkinje cell layer. Belongs to the UPF0220 family.