ChEBI: Genistein is 7-Hydroxyisoflavone with additional hydroxy groups at positions 5 and 4'. It is a phytoestrogenic isoflavone with antioxidant properties. It has a role as an antineoplastic agent, a tyrosine kinase inhibitor, an EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor, a phytoestrogen and a plant metabolite. It is a conjugate acid of a genistein(1-).NCI Thesaurus (NCIt): Genistein is a soy-derived isoflavone and phytoestrogen with antineoplastic activity. Genistein binds to and inhibits protein-tyrosine kinase, thereby disrupting signal transduction and inducing cell differentiation. This agent also inhibits topoisomerase-II, leading to DNA fragmentation and apoptosis, and induces G2/M cell cycle arrest. Genistein exhibits antioxidant, antiangiogenic, and immunosuppressive activities. (NCI04)