This gene encodes a member of the SPFH domain-containing family of lipid raft-associated proteins. The encoded protein is localized to lipid rafts of the endoplasmic reticulum and plays a critical role in inositol 1,4,5-trisphosphate (IP3) signaling by mediating ER-associated degradation of activated IP3 receptors. Mutations in this gene are a cause of spastic paraplegia-18 (SPG18). Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene.