A semisynthetic derivative of podophyllotoxin, a substance extracted from the mandrake root Podophyllum peltatum. Possessing potent antineoplastic properties, etoposide binds to and inhibits topoisomerase II and its function in ligating cleaved DNA molecules, resulting in the accumulation of single- or double-strand DNA breaks, the inhibition of DNA replication and transcription, and apoptotic cell death. Etoposide acts primarily in the G2 and S phases of the cell cycle. or A drug used to treat testicular and small cell lung cancers. It is also being studied in the treatment of several other types of cancer. Etoposide blocks certain enzymes needed for cell division and DNA repair, and it may kill cancer cells. It is a type of podophyllotoxin derivative and a type of topoisomerase inhibitor.