Presented below are antibodies against ESR1, the gene symbol for the human protein, Estrogen receptor 1. It may also be known as ER-alpha, ERa, and NR3A1. This protein is a member of the Nuclear hormone receptor family, NR3 subfamily, and has a predicted amino acid length of 595 and a mass of 66.2 kDa. There are currently 4 reported isoforms. Orthologs for this gene are also found in the mouse, rat, zebrafish and frog. ESR1 is implicated in diseases such as breast, ovarian and endometrial cancers and in the rare estrogen insensitivity syndrome.