Protein disulfide isomerases (EC 5.3.4.1), such as PDIA6, are endoplasmic reticulum (ER) resident proteins that catalyze formation, reduction, and isomerization of disulfide bonds in proteins and are thought to play a role in folding of disulfide-bonded proteins (Hayano and Kikuchi, 1995 [PubMed 7590364]).[supplied by OMIM, Mar 2008]