NCIt definition : An agent targeting the phosphatidylinositol 3 kinase (PI3K) and mammalian target of
rapamycin (mTOR) in the PI3K/mTOR signaling pathway, with potential antineoplastic
activity. PI3K/mTOR kinase inhibitor PF-04691502 inhibits both PI3K and mTOR kinases,
which may result in apoptosis and growth inhibition of cancer cells overexpressing
PI3K/mTOR. Activation of the PI3K/mTOR pathway promotes cell growth, survival, and
resistance to chemotherapy and radiotherapy; mTOR, a serine/threonine kinase downstream
of PI3K, may also be activated independent of PI3K.;