ERBB2 and gastroesophageal junction adenocarcinoma: Although trastuzumab, the antibody against ERBB2, is already approved for EAC, it is important to consider how far these findings extend to the similarly related gastroesophageal adenocarcinomas (Supplementary Figure 9), gastric adenocarcinomas, and gastroesophageal junction adenocarcinomas, where ERRB2 may be overexpressed as well (Battaglin et al., 2018).