<prompt> Estrogen receptors are seen inMicrosomesMembrane boundNucleusMitochondria  <response>: The estrogen receptor ER is a ligand-activated enhancer protein that is a member of the steroidnuclear receptor superfamily.Two genes encode mammalian ER: ERa and ERb.ER binds to specific DNA sequences called estrogen response elements EREs with high affinity and transactivates gene expression in response to estradiolRef: DM Vasudevan, 7th edition, page no: 57 