PI3Kγ inhibitor 4 is a potent, selective and orally active inhibitor of PI3Kγ , with an IC 50 of 40 nM. PI3Kγ inhibitor 4 shows ∼7, 43, and 18-fold selectivity for PI3Kγ over the α, β, and δ isoforms, respectively. PI3Kγ inhibitor 4 can be used for the research of airway inflammation.