PIK3CA and breast cancer: Pradip et al., conducted a study using BRCA-competent breast cancer-bearing mouse models and showed that GDC-0980 (a dual PI3K-mTOR inhibitor) enhanced the antitumor effects of the PARP inhibitor ABT888 plus carboplatin by inhibition of tumor cell proliferation and tumor-induced angiogenesis; however, combination with GDC-0941, a pan-PI3K inhibitor, failed to suppress tumor growth in MDA-MB231 breast cancer cells (De et al., 2014).