PIK3CD and acute myeloid leukemia: Finally, aberrant AML cell activation of mTORC1, causing the phosphorylation of downstream targets such as p70S6K, S6RP, and 4EBP1, has also been detected for a large majority of patients [97], but this activation of mTORC1 may not depend on PI3K-Akt activity alone in human AML [98].