Ethanolic extracts of the rhizomes are known as podophyllin, which is included in many pharmacopoeias for the topical treatment of warts and condylomata acuminate, which are benign tumours. Podophyllin resin is highly irritant and unpleasant and cannot be used systemically. The main natural product is the podophyllatoxin lignin class (Chapter 6) of which podophyllotoxin was the first to be isolated in 1880 and the structure proposed in 1932. There are many components in podophyllin; the most important from the antitumour perspective are the lignans. Podofilox is a purified form of podophyllin which acts as a cell poison against cells undergoing mitosis, and although this extract is not a systemic chemotherapeutic agent it is used topically in creams as a treatment for genital warts.