BCL2 and chronic myelogenous leukemia, BCR-ABL1 positive: Our results also showed hBMMSC-Exo could decrease the sensitivity of CML cells to tyrosine kinase inhibitors and promote IM resistance of CML cells by reducing apoptosis and increasing the proliferation of both cells in vivo, while one recent study indicated that exosomes derived from human umbilical cord mesenchymal stromal cells (hUCMSC-Exo) promoted IM-induced cell viability inhibition and apoptosis by enhancing the increased Bax expression and the decreased Bcl-2 expression and activating Caspase9 and Caspase3 [32].