Rearrangements of the RNA binding protein, EWSR1, characterize various malignancies including Ewing sarcoma (EWSR1/ETS), desmoplastic small round cell tumor (EWSR1/WT1), and some acute lymphoblastic leukemias (EWSR1/ZNF384) [60]–[62]. The gene discussed is WT1; the disease is Ewing sarcoma.