ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Recent studies have found that blast crisis in chronic myelogenous leukemia is closely related to chromosomal abnormalities and genetic mutations.[9–11] In addition to BCR/ABL1 fusions, there are mutations in p53,[12,13]RUNX1,[14,15]RAS,[16] and other genes during a CCML blast crisis.