This gene belongs to the TMED (transmembrane emp24 domain-containing) protein family, which is involved in the vesicular trafficking of proteins. The protein encoded by this gene was identified by its interaction with interleukin 1 receptor-like 1 (IL1RL1) and may play a role in innate immunity. This protein lacks any similarity to other interleukin 1 ligands. Alternative splicing results in multiple transcript variants of this gene.