Akt functions as a key component in multiple signaling pathways to promote cell survival by mediating resistance to apoptosis. Akt inhibitor X is a cell permeable phenoxazine derivative that suppresses insulin-like growth factor 1 (IGF-1)-stimulated phosphorylation of Akt with an IC value of 1-2 μM. This compound has been shown to block IGF-1-stimulated nuclear translocation of Akt in Rh1 cells and to inhibit the growth of Rh1, Rh18, and Rh30 cells with IC values of 2-5 μM. Inhibition of Akt phosphorylation by 5 μM of this compound strongly correlates to the inhibition of the downstream targets, mTOR, p70S6 kinase, and S6 ribosomal protein and to an increase in apoptosis.