Figure 3.
Results of HER2 IHC, HER2 silver in situ hybridization (SISH), and trastuzumab IHC in two cases among consecutive gastric cancer patients. Case 1 shows negativity by HER2 IHC, however, HER2 amplification was confirmed by SISH, and was 3+ by trastuzumab IHC. Case 2 showed 3+ by both HER2 and trastuzumab IHC, and HER2 gene amplification was observed as well.