Both MLL1 (KMT2A) and SETD1B (KMT2G) are highly expressed by Ewing sarcoma cell lines, with expression levels comparable to those of several hematological malignancies known to be driven by MLL rearrangements and/or amplification [9] (Figure 1A and Supplementary Figure S1). The gene discussed is KMT2A; the disease is Ewing sarcoma.