ERBB2 and gastric cancer: Between January 2006 and April 2015, we collected clinicopathological data from 115 patients who were diagnosed with inoperable, locally advanced, recurrent, or metastatic HER2-positive gastric cancer patients, and from participants in trastuzumab clinical trials at the Yonsei Cancer Center [NCT01041404 (ToGA trial), NCT01736410, and NCT0140696].