ERBB2 and breast carcinoma: The criteria used in the clinical trial (NCT1367002), leading to trastuzumab’s approval and the formulation of associated NCCN guidelines, were based on the ISGyP modified 2013 ASCO/CAP HER2 testing recommendations in breast carcinoma, defining IHC 3+ as strong, complete circumferential or basolateral membranous staining in 30% of neoplastic cells [16].