CD38 and acute myeloid leukemia: Our second unexpected finding was that, when compared to normal CD34+ cells from stem cell harvests, p-mTOR was low, 4E-BP1 was 2.6-fold elevated in AML blasts, and p-rpS6 was increased by 22-fold in the blasts, with an additional 95% elevation in leukaemic CD34+CD38- cells.