Trabectedin (Ecteinascidin 743; ET-743) is a tetrahydroisoquinoline alkaloid with potent antitumor activity. Trabectedin binds to the minor groove of DNA, blocks transcription of stress-induced proteins, induces DNA backbone cleavage and cancer cells apoptosis, and increases the generation of ROS in MCF-7 and MDA-MB-453 cells. Trabectedin has the potential for soft tissue sarcoma and ovarian cancer research.