CD44 expression is regulated by the PI3K/Akt/mTOR pathway in APL cells. (A-B) Protein levels of CD44 and PI3K/Akt/mTor signals in APL and NB4 cells treated with/without the PI3K inhibitor BKM. The mean gray value was measured by using ImageJ. (C) Representative immunofluorescence images showing the presence of BKM. Scale bar, 10 µm. (D) K_s of the clot was measured as previously described. (E) Clot lysis assays were performed as previously described. (F-G) Leukemia cells with/without previous treatment with BKM were mixed with activated platelets. Leukemic cell–platelet complexes were detected by using flow cytometry. (H) The schema image of leukemic cells binding platelets and the signaling regulating CD44 expression in APL cells. *P < .05, **P < .01. Each data set is from at least 5 experiments. IgG, immunoglobulin G; MPO, myeloperoxidase.