PIK3CA and small cell lung carcinoma: Expanding on our previous observations that 1) sensitivity to PARP inhibition is related inversely to PI3K/mTOR pathway activity [5] and 2) PARP inhibition increased PI3K/mTOR signaling, we tested the anti-proliferation efficacy of a PI3Kα inhibitor (BKM-120) in our panel of 50 SCLC cell lines.