PIK3CA and breast carcinoma: first reported a systematic investigation of activating mutations of NECB in 2014, identifying mutations in 5 of 15 (33%) NECs, including PIK3CA mutation in 20% of NECB and rare mutations in breast cancer (fibroblast growth factor receptor 1 (FGFR1), FGFR4, kinase insert domain receptor (KDR), and HRAS) (35).