Estrogen is a steroid hormone that acts in the body in both beneficial and detrimental ways. It plays a crucial role in many human processes including coagulation, bone formation, and development of sexual organs. However, estrogen is also associated with the proliferation of breast cancer. Estrogen activates the estrogen receptor (ER), a ligand-dependent transcription factor that regulates gene expression by binding to specific DNA elements and promoting or repressing transcription
