A portion of amino acids 290-560 was used as the immunogen for the Estrogen Receptor alpha antibody. The epitope of this mAb is between amino acids 300-550.
This mAb is specific to ER alpha and shows minimal cross-reaction with other members of the family. ER is an important regulator of growth and differentiation in the mammary gland. Presence of ER in breast tumors indicates an increased likelihood of response to anti-estrogen (e.g. tamoxifen) therapy.