Conversely, the phase II LORELEI trial did not reveal a significant divergence in pathologic complete response (pCR) rates between the taselisib and letrozole combination and letrozole alone in the neoadjuvant treatment of early-stage, ER+/HER2- breast cancer patients, whether they harbored PIK3CA mutations or not (40). This evidence concerns the gene PIK3CA and breast carcinoma.