Combination therapy consisting of Trastuzumab and Buparlisib, a PI3K inhibitor, resulted in a 17% partial response (Saura et al., 2014), and mTOR inhibition combined with aromatase inhibitors in patients with hormone-receptor positive advanced breast cancer showed extended progression-free survival (Baselga et al., 2012). This evidence concerns the gene PIK3CA and breast cancer.