Preclinical studies of AML suggest that mTOR pathway signalling and suppression of protein translation may play a part in the mechanism of action of AZD1208.19 Consistent with these studies, significant reductions in 4EBP1 S65 were seen in a subset of patients while more modest decreases in 4E-BP1 T37/46 and mTOR S2448 were also noted. Here, EIF4EBP1 is linked to acute myeloid leukemia.