What is the definition or description of: estrogen receptor?

Estrogen Receptor: Estrogen is a hormone that is produced by the ovaries. The hormones have an effect on cells. The way the hormones produce a response is by binding to receptor on the cell.

See answer details.: An estrogen receptor is a protein found on some cells in the human body that is activated by the hormone estrogen. Once activated, the receptor sends a signal to the cell nucleus to activate certain genes. In breast cancer, the tumor is tested to determine if estrogen receptors are present on the malignant cells; if they are present, then anti-estrogen therapy is given as a part of the treatment.