This gene encodes a noncatalytic member of the protein disulfide isomerase (PDI) family of endoplasmic reticulum (ER) proteins. The canonical protein has an N-terminal signal sequence, two thioredoxin (TRX)-like domains and a C-terminal ER-retention sequence. Alternative splicing results in multiple transcript variants encoding distinct isoforms; some of which lack domains present in the canonical protein. [provided by RefSeq, Dec 2016].