BCR and chronic myelogenous leukemia, BCR-ABL1 positive: In our previous studies on BCR::ABL1-positive leukemias [7, 10–12], we defined “CML-like” leukemias, diagnosed as ALL but exhibiting BCR::ABL1 fusion in multipotent, not fully leukemic progenitors, biologically resembling CML in lymphoid blast crisis.