PARP1 and breast carcinoma: Significantly, we found all four PIK3CA mutated breast cancer cell lines were sensitive to MK- 2206 (IC50<1 versus >15 μM, P value=0.003, Mann–Whitney) in both viability and colony assays (Fig. 4d, Supplementary Fig. 5e) with increased cleaved PARP and decreased phospho-PRAS40, S6K, 4EBP1 and BAD (Supplementary Fig. 5f).