VLAHOS ET AL.: 'A specific inhibitor of phosphatidylinositol 3-kinase, 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002)', JOURNAL OF BIOLOGICAL CHEMISTRY, vol. 269, no. 7, 18 February 1994 (1994-02-18), pages 5241 - 5248, XP002934871