Given the important role of the estrogen receptor ( ER ) in the development and physiology of the breast , it is essential to delineate the mechanisms responsible for its failed expression in some breast tumors .
given the important role of the estrogen receptor ( er ) in the development and physiology of the breast , it is essential to delineate the mechanisms responsible for its failed expression in some breast tumors .
O O O O O O B-protein_molecule I-protein_molecule O B-protein_molecule O O O O O O O O B-body_part O O O O O O O O O O O O O O O B-body_part O O