To determine the functional consequences of increased INPP4B expression in PIK3CA-mutant ER+ breast cancer, GFP-INPP4B was expressed in MCF-7 and T47D ER+ breast cancer cells (Supplementary Fig. 2a), which harbor hyperactivating PIK3CAE545K and PIK3CAH1047R mutations, respectively. This evidence concerns the gene PIK3CA and breast carcinoma.