ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: Evaluation of the phosphorylation status of the BCR-ABL-specific substrate CRK-like protein (CRKL) revealed the presence of a phosphorylated form of CRKL (p-CRKL) in CML, but not in the control BM iCD34+ and iCD34− cells (Fig. 3c), thus providing evidence that BCR-ABL is active in CML iPSC-derived hematopoietic progeny.