Background
In order to provide potential diagnostic markers and to identify potential targets for breast cancer therapy, gene products that are differentially expressed between benign and malignant cells have been isolated and identified by a combination of PCR-selected suppression subtractive libraries [1, 2] and inhouse cDNA microarrays, screened using mRNAs from human breast cancer specimens. A number of the cDNAs were differentially expressed by greater than twofold, including the one for AGR2, the secreted human homologue of a Xenopus developmental protein.