ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: We also evaluated Bcr-Abl1 mRNA expression in CML KITlo and c-KIThi LT-HSCs using qRT-PCR (Figure 1G) and BCR-ABL signaling by measuring phosphorylated STAT5 (p-STAT5) levels in CML KITlo and c-KIThi LT-HSCs using intracellular flow cytometry (Figure 1H).