TXNDC5 is a protein-disulfide isomerase. Its expression is induced by hypoxia and its role may be to protect hypoxic cells from apoptosis. ERp19 and ERp46 are two newly discovered ER luminal proteins, related to protein disulphide isomerase. Western and Northern blot analyses have revealed that both ERp19 and ERp46 and their respective mRNAs are highly expressed in the liver as compared with other tissues. Both proteins are enriched in purified liver ER vesicles and were localized specifically to the ER in McA-RH7777 hepatocytes. See Knoblach et al. for details.