ABL1 and chronic myelogenous leukemia, BCR-ABL1 positive: As shown in Fig. 4a, after treatment with 5 μM imatinib, CML iCD34+ cells moved away from non-treated CML iCD34+ cells toward non-treated control BM iCD34+ cells in the dimension defined by principal component PC1 and PC2, i.e. became more similar to control BM iCD34+ cells, thereby suggesting the important role of BCR-ABL signaling in establishing the unique transcriptional signature of neoplastic cells in CML.