GDC0980, a orally-available, thienopyrimidine-based, ATP-competitive dual inhibitor of PI3K class I isoforms (IC50 of 5, 27, 7, and 14 nM for PI3Ka, b, d, and g) and mTOR (Ki of 17 nM). [1] GDC0980 potently inhibits signal transduction (Thr308, Ser473) downstream of both PI3K and mTOR and showed most potent antitumor activity in breast, prostate, and lung cancer (IC50