For example, while SF3B1 mutation occurs at high frequency in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), the only isogenic SF3B1 mutant myeloid cell line is in K-562, a chronic myelogenous leukemia (CML) cell line (4). The gene discussed is SF3B1; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.