ERBB2 and gastric cancer: Both 1A12 and 1F11 antibodies showed slightly increased anti-proliferative activities as a single agent compared to hz1E11 on NCI-N87 and OE-19 gastric cancer cell lines that overexpress HER2 (Fig 5A and 5B), whereas in combination with trastuzumab, their anti-proliferative activities was superior to that trastuzumab alone and equivalent to hz1E11 plus trastuzumab.