Calreticulin (CALR) is calcium-binding chaperone that promotes folding, oligomeric assembly and quality control in the endoplasmic reticulum (ER) via the calreticulin/calnexin cycle. This lectin interacts transiently with almost all of the monoglucosylated glycoproteins that are synthesized in the ER. CALR also: Interacts with the DNA-binding domain of NR3C1 and mediates its nuclear exportInvolved in maternal gene expression regulationMay participate in oocyte maturation via the regulation of calcium homeostasis