This gene encodes a member of a family of single pass transmembrane domain proteins that function as ancillary subunits to voltage-gated potassium channels. Members of this family affect diverse processes in potassium channel regulation, including ion selectivity, voltage dependence, and anterograde recycling from the plasma membrane. Variants of this gene are associated with idiopathic ventricular fibrillation and Brugada syndrome. [provided by RefSeq, Nov 2016].