The rationale for testing trabectedin was based on the following: (i) trabectedin was the only drug among several tested that induced marked growth suppression against an ex vivo CIC-DUX4–expressing mouse model (9); (ii) it was approved for clinical use in patients with other soft tissue sarcomas that have proven to be resistant to standard chemotherapy and other targeted therapies and/or metastasis; and (iii) it has ability to impair the function of HMGA proteins (18), which may confer additional value in the context of CDS. Here, DUX4 is linked to soft tissue sarcoma.