Oestrogen receptor. Molecular model of human oestrogen-related receptor gamma (EER-gamma, blob) with a bisphenol A molecule (ball-and-stick) bound to its ligand binding domain (dark area at centre). Oestrogen receptors are cytoplasmic proteins that bind oestrogens and then migrate to the nucleus where they can regulate DNA transcription. Bisphenol A is used in the plastic industry as an antioxidant. It is a synthetic oestrogen that lowers sperm count in men and is also thought to disrupt foetal development.