The PI3k/Akt pathway plays a role in ALL blast apoptosis. (A) Flow cytometry analysis of apoptosis, by annexin V-FITC staining, of ALL blasts incubated for 24 hours with and without rapamycin (100 ng/mL) or wortmannin (1 μM). The percentages over the bars indicate the amount of annexin V-positive cells. (B) Western blotting assay of phospho-Akt, at Ser 473 or Thr 308, in cell lysates from the same samples.