An inhibitor of PI3K p110α (IC50 = 2 nM in an enzyme assay); selective for p110α over p110β, p110γ, and PI3K C2β (IC50s = 16, 660, and 220 nM, respectively); inhibits mTOR (IC50 = 49 nM); inhibits proliferation in A375 melanoma cells (IC50 = 0.58 μM)