ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: However, there are certain leukemia cases, for instance, acute promyelocytic leukemia (APL) patients with mutations in PML‐RARα, NPM1, and FLT3‐ITD fusion genes, and CML patients with BCR‐ABL1 gene, show significant resistance to chemotherapeutic drugs, leading to disease progression and even death.4, 5