Researchers Have Determined That the Growth of Hormone-Responsive Breast Cancer

Researchers have determined that the growth of hormone-responsive breast cancer cells depends upon ____.

A) the relative concentrations of ERα and ERβ in the tumor cells
B) the ability of ERβ to stimulate cancer cell growth
C) the ability of ERα to inhibit cancer cell growth
D) whether DNA binding sites exists for ERα, but not ERβ
E) the relative concentrations of estrogen and testosterone in breast tissue