The protein encoded by this gene is a member of the FK506-binding protein family of peptidyl-prolyl cis-trans isomerases. The encoded protein is found in the lumen of the endoplasmic reticulum, where it is thought to accelerate protein folding. Defects in this gene are a cause of a type of Ehlers-Danlos syndrome (EDS). Both a protein-coding variant and noncoding variants are transcribed from this gene. [provided by RefSeq, Mar 2012].