STAT3 and chronic myelogenous leukemia, BCR-ABL1 positive: In conclusion, we found that coumarin derivative decreased cell viability in both TKI sensitive and resistant CML cells in vitro, compound DBH2 in combination with imatinib suppressed leukemic development in vivo, and it induced apoptosis in CML cells depend on the activation of STAT3/STAT5/caspase-3 pathways.