Targeting of EWSR1::FLI1 to these GGAA microsatellites results in recruitment of the SWI/SNF chromatin remodeling complex and p300 histone acetyltransferase, aberrant chromatin accessibility, and the establishment of de novo enhancers through which EWSR1::FLI1 activates the expression of many genes shown to be necessary for Ewing sarcoma proliferation (7, 8). Here, EWSR1 is linked to Ewing sarcoma.