PI3Kδ-IN-14 (Compound (S)-29) is a selective PI3Kδ inhibitor ( IC 50 : 0.8 nM, K d : 84.8 nM). PI3Kδ-IN-14 binds to the ATP-binding site of the kinase domain of PI3Kδ. PI3Kδ-IN-14 has anti-inflammatory activity by inhibiting the PI3K/AKT pathway. PI3Kδ-IN-14 ameliorates acute lung injury (ALI).