Trabectedin [Ecteinascidin 743, Yondelis, ET 743, NSC 684766] is one of a series of compounds isolated from the Caribbean tunicate, Ecteinascidia turbinata.1 It interacts with the minor groove of DNA and alkylates guanine at the N2 position. In this manner, it is thought that trabectedin may affect various transcription factors involved in cell proliferation. Trabectedin blocks the G2 phase of the cell cycle while cells in G1 are most sensitive to the drug. It also inhibits the overexpression of the multidrug resistance-1 gene (MDR-1) coding for the P-glycoprotein, a major factor responsible for cells developing resistance to cancer drugs.