Out of a total of 95 breast cancer samples, 5 breast-cancer samples did not have mTOR-pathway activation, and all 5 (100%) of these had PIK3CA and PTEN mutations compared to 51/90 (57%) in the breast-cancer samples with mTOR-pathway activation (χ2p=0.0134; Table 2). Here, PTEN is linked to breast carcinoma.