ERBB2 amplifications fell most frequently in breast cancer (80/503, 15.9%), stomach cancer (83/998, 8.3%), biliary tract cancer (57/840, 6.8%), intestine cancer (8/179, 4.5%), and esophagus cancer (7/195, 3.6%, Figure 1A). This evidence concerns the gene ERBB2 and biliary tract cancer.