This non-competitive reversible inhibitor induces apoptotic responses in Ewing sarcoma cell lines through engagement of the endoplasmic reticulum stress response, reverses the EWS/ETS transcriptional signature, impairs several EWS/ETS-associated oncogenic phenotypes, and shows single-agent efficacy in multiple xenograft models of Ewing sarcoma [10, 11]. The gene discussed is EWSR1; the disease is Ewing sarcoma.