PIK3CD and breast carcinoma: 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.