We have previously shown that patients with ER+ tumours harbouring high p-AKT(Ser473), p-AKT(Thr308), p-mTOR or p-p70S6K expression who did not receive adjuvant tamoxifen also had a decreased risk of breast cancer recurrence.18 Other groups have analysed the prognostic significance of PIK3CA mutations or the expression of individual proteins. Here, PIK3CA is linked to breast cancer.