One of the subgroups with less favorable prognosis is defined as BCR-ABL1-like (Ph-like) ALL and accounts for up to 10%–15% of all pediatric ALL cases and for up to 20%–25% of ALLs in adults.7,8 Unlike the BCR-ABL1-positive ALLs, the BCR-ABL1-like ALLs do not contain the BCR-ABL1 fusion, yet their gene expression profile is similar to that of BCR-ABL1-positive ALL. This evidence concerns the gene ABL1 and acute lymphoblastic leukemia.