Human ESR1 Gene Mutation Detection Assays

ESR1 (estrogen receptor 1), also known as estrogen receptor alpha (ERα) or NR3A1 (nuclear receptor subfamily 3, group A, member 1), is one of the two main types of estrogen receptors. Estrogen receptors are nuclear receptors activated by the sex hormone estrogen. In humans, ERα is encoded by the ESR1 gene (estrogen receptor 1).

Hormone receptor (HR)-positive breast cancers account for approximately 70% of all breast cancers. Endocrine therapy is the primary treatment for these patients, but its efficacy is affected by drug resistance. ESR1 mutations leading to the activation of ligand-independent pathways are an important cause of endocrine drug resistance in ER-positive breast cancer.