CHMFL-PI3KD-317 is a highly potent, selective and orally active PI3Kδ inhibitor, with an IC 50 of 6 nM, and exhibits over 10-1500 fold selectivity over other class I, II and III PIKK family isoforms, such as PI3Kα (IC 50 , 62.6 nM), PI3Kβ (IC 50 , 284 nM), PI3Kγ (IC 50 , 202.7 nM), PIK3C2A (IC 50 , >10000 nM), PIK3C2B (IC 50 , 882.3 nM), VPS34 (IC 50 , 1801.7 nM), PI4KIIIA (IC 50 , 574.1 nM) and PI4KIIIB (IC 50 , 300.2 nM). CHMFL-PI3KD-317 inhibits PI3Kδ-mediated Akt T308 phosphorylation in Raji cells, with an EC 50 of 4.3 nM. CHMFL-PI3KD-317 has antiproliferative effects on cancer cells.