SYK and acute myeloid leukemia: Confirming target engagement by PU-H71, we observed that the reduction in peripheral blood blast levels was paralleled by a rebalance in the activity of PPI networks, as evidenced by a decrease in the activity of signaling pathways (see levels of phospho-SYK (Y525/526), phospho-STAT5 (Y694), and phospho-S6 (S235/S236) in the bottom panels of Fig. 2f), Furthermore, PU-H71 treatment also rebalanced the activity of PPI networks in AML progenitor (CD34 + ) and stem cell populations (CD34 + CD38-CD123 + ) (Fig. 3a).