ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Atypical Chronic Myelogenous Leukemia (aCML), characterized by BCR/ABL1 negative and Ph chromosome-negative, is a rare and aggressive leukemia variant with poor prognosis, and although it does not exhibit the conventional CML indicators, it possesses characteristics such as hyperleukocytosis and dysgranulopoiesis.