EGFR and breast cancer: Several studies have recently revealed that mutations at the residue D1067 (PIK3CBD1067Y, D1067A, or D1067V) display oncogenic potential, and confer resistance to erlotinib [an inhibitor of epidermal growth factor receptor (EGFR)] in non-small-cell lung cancer or decrease the sensitivity of breast cancer cells to pictilisib (also known as GDC-0941, an inhibitor of p110α/δ) (77, 78).