PIK3CB and chronic myelogenous leukemia, BCR-ABL1 positive: The PI3k/Akt/mTOR pathway is one of the multiple signaling pathways that are activated by BCR-ABL in CML cells, so drugs targeting key molecules such as PI3K, Akt and mTOR have been reported to exert beneficial effects in CML progenitor and stem cell populations (Table 1).