These findings are in line with previous reports showing that the use of combined pan‐PI3K class I and EGFR inhibitors produced synergistic responses in basal‐like breast cancers (She et al, 2016) and that inhibition of PI3Kβ relieves a feedback activation of PI3Kα (Schwartz et al, 2015), and they add another piece of information to the complex network that allows PTEN‐null breast cancer cells to survive PI3K pathway inhibition. This evidence concerns the gene PIK3CD and breast cancer.