ERBB2 and esophageal cancer: This approach reconfirmed the well-established ERBB2 oncogene addiction in models of breast cancer, but also established ERBB2 addiction/KGD in models of esophageal cancer (Figures 3B and 3C), where ERBB2 is recurrently amplified/overexpressed in 20% of tumors (Bang et al., 2010).