Anterior gradient homolog 2 (AGR2) is a human protein originally discovered in Xenopus laevis, encoded for by the gene of the same name. In Xenopus AGR2 plays a role in cement gland differentiation, however in human cancer cell lines high levels of AGR2 correlate with downregulation of the p53 response and AGR2 levels are elevated in the preneoplastic tissue Barrett's oesophagus.

The deduced 175-amino acid soluble AGR2 protein, which is 91% identical to the mouse protein and 47% identical to the frog protein, contains a signal peptide. Northern blot analysis revealed strongest expression of 0.9- and 1.6-kb AGR2 transcripts in lung and in all ER-positive breast carcinoma lines tested; weaker expression was detected in pancreas.