PIK3CB and leukemia: Besides miRNAs which directly target mTOR components, several other miRNAs have been reported to targets that are upstream (mir-22, miR-26, miR-150, miR-193, miR-223, miR-3151) [75,76,77,78,79] or downstream (miR-29, miR-181) [80,81,82] of mTOR signaling, highlighting the importance of the PI3K/Akt/mTOR axis in leukemias.