Etoposide is marketed as Vepesid for small cell lung cancer, testicular cancer and lymphomas; teniposide is also used in the treatment of brain tumours, Podophyllotoxin binds to tubulin and is a member of the ‘spindle poison’ group of agents and functions by preventing microtubule formation. Etoposide and teniposide work via a different mechanism by inhibiting the enzyme topoisomerase II preventing DNA synthesis and replication. The difference in mechanism is attributable to the small adjustment in structure with etoposide and teniposide being 4’-demethyl compounds and having different stereochemistry at position C1.