Potent and selective PI 3-kinase β inhibitor (IC50 values are 0.007, 0.1, 3.5 and 5 μM for the β, δ, γ and α isoforms, respectively). Shows >1,000-fold selectively for PI 3-kinase β over a range of other kinases. Inhibits thrombus formation in animal models. Purity 98%. MW (observed): 364.44