FLT3 and acute myeloid leukemia: In FLT3-ITD+ WT cells, lower size PEG (PEG2000 and PEG4000) had no impact on the release of G-CSF, while larger PEG (PEG6000 and PEG8000) had a size-dependent inhibitory effect, an effect also observed in AML-ETO and MLL-ENL-transformed cells (Fig. S6E, F).