EWSR1 and Ewing sarcoma: First molecular insights into how biomolecular condensation can mediate malignant transformation were obtained from studies of the EWS::FLI1 fusion protein, which is a molecular hallmark of Ewing’s sarcoma.5 EWS::FLI1 acts as an oncogenic TF that forms chromatin-associated nuclear condensates at highly repetitive GGAA microsatellite regions.15 Activation of the oncogenic transcriptional program of EWS::FLI1 depends on the recruitment of the chromatin remodeling BRG/BRM-associated (BAF) protein complex.