[5][6][7] The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters.

This protein forms a heterodimer with ABCB2 in order to transport peptides from the cytoplasm to the endoplasmic reticulum.

Mutations in this gene may be associated with ankylosing spondylitis, insulin-dependent diabetes mellitus, schizophrenia,[8] and celiac disease.

Alternative splicing of this gene produces two products which differ in peptide selectivity and level of restoration of surface expression of MHC class I molecules.

[9] This article incorporates text from the United States National Library of Medicine, which is in the public domain.