Experiments showing that inhibition of all class I PI3K isoforms by copanlisib was less effective than panPI3K/mTOR inhibition by gedatolisib in cell lines with wild type PIK3CA and PTEN (Supplementary Fig. 9) suggest that inhibition of mTOR may be required for effective cell growth inhibition in this BC subpopulation. The gene discussed is PTEN; the disease is breast cancer.