Activation of the PI3K/mTOR pathway in response to PTL. Representative immunoblot analyses for 3 primary AML specimens treated with 5μM PTL for 6 hours. Blots were probed as indicated with antibodies against either phospho-p70 S6 kinase (T421/S424), total p70 S6 kinase, phospho-p65 (S536), or β-actin.