In addition to RNA Helicase A, which interacts with the EWS–FLI1 fusion protein and is being evaluated in clinical trials as a druggable vulnerability, histone lysine demethylase (LSD1) is another interaction partner of FET-fusion sarcoma (including Ewing sarcoma) with therapeutic potential for targeted disruption [14]. The gene discussed is FLI1; the disease is Ewing sarcoma.