This fusion is crucial to the epigenetic pathogenesis of Ewing sarcoma through its participation in abnormal chromatin remodelling, via DNA binding domains of EWSR1-FL1 which recognize microsatellites with GGAA repeats, which, in turn, leads to recruitment of histone acetyltransferases to the nucleosome, causing loosening of the tertiary structure of DNA, enabling gene transcription [41]. This evidence concerns the gene EWSR1 and Ewing sarcoma.