MTOR and chronic myelogenous leukemia, BCR-ABL1 positive: The BCR-ABL1 oncoprotein was found to upregulate expression of VEGF in CML cells, and analysis of signaling pathways downstream of BCR-ABL1 revealed that the mammalian target of rapamycin (mTOR) contributes to BCR-ABL1-dependent expression of VEGF [27].