An ETV6 split FISH was requested,29 but yielded negative results because of EML4 being the 5′ fusion partner.30 The KMT2A-AFDN fusion detected in an acute myeloid leukemia sample was readily identified by RNA-seq, but undetected in routine diagnostics, probably because of the low resolution of karyotyping or nonmitosis of leukemic cells (Fig 4A). The gene discussed is KMT2A; the disease is acute myeloid leukemia.