breast cancer The main challenges of cancer diagnosis and treatments are because the symptoms of several cancers, including in cases of breast cancers are easily ignored, or incorrectly credited to other ailments. A weapon of attack for these cancers could be found in monitoring irregularities or changes in receptor functions. Predictive biomarker assays seem to be the golden standard for therapeutic interventions of today as they allow insight into the molecular environment and allow for species of interest to be quantified. The estrogen receptor (ER) is no exception to this concept as the observation of this receptor’s activity allows for insight into growth and proliferation and allows for differentiations to be made between various intercellular environments. Complex biochemical reactions exhibited by the estrogen receptor are necessary for the mediation of cellular interactions in response to various cell-altering factors including ligands, cofactors, and other simulative complexes. Monitoring tumor development with the estrogen receptor test The estrogen receptor is the main regulator of cellular functions including cell growth, and proliferation, and can serve as a means of inter-cellular differentiation. Monitoring the activity of the ER via the ERT is necessary as it plays an essential role in normal breast development and function, as well as in cancerous situations. Accurate measurements of the ER activities are critical in the care and progression monitoring of breast cancers as the ER can serve as an indicative biomarker as it is a potential predictor for the clinical responses of a patient to cancer treatments. It has been proven that breast cancer patients who present an ER-positive status are most likely to respond to cancer treatments through endocrine therapy. Measuring the ER activity is essential in the care of breast patients as the Estrogen receptor test allows for informed decisions to be made for the future best treatments for cancer patients. Estrogen receptor test in mammary epithelial cancer In approximately 70% of diagnosed cases of breast cancers, the ER activity is over-expressed. Growing exposure of the mammary epithelium to estrogen is related to the risk of breast cancer as the binding of estrogen to the HER2 (cancerous breast cell receptor) in mammary cells causes a rise in the division and cell synthesis. This ultimately leads to a higher risk of replication errors, and the disruption of the normal cellular processes results in errors in apoptosis, cellular proliferation, or DNA repair. The ERT has been suggested as a