Estrogen receptor-beta (ESR2) is a member of the superfamily of nuclear receptors,which can transduce extracellular signals into transcriptional responses. It binds estrogens with an affinity similar to that of ESR1,and activates expression of reporter genes containing estrogen response elements (ERE) in an estrogen-dependent manner. DNA-binding by ESR1 and ESR2 is rapidly lost at 37 degrees Celsius in the absence of ligand while in the presence of 17 beta-estradiol and 4-hydroxy-tamoxifen loss in DNA-binding at elevated temperature is more gradual.