In particular, let-7a is a direct EWSFLI-1 target which plays a key role in ES pathogenesis; let-7a acts as tumor suppressors thanks to its ability to silence numerous genes that encode oncogenic proteins (such as high-mobility group AT-hook (HMGA2), a DNA binding protein highly expressed in cancer cells), resulting in a reduction of tumor growth [105]. The gene discussed is EWSR1; the disease is Ewing sarcoma.