ERBB2 and gastric cancer: Although HER2-targeted therapy has shown improved clinical outcomes in HER2-positive breast and gastric cancer patients (Slamon et al. 2001; Bang et al. 2010; Oh and Bang 2020; Olson 2012), limited data is available regarding the frequency of ICCs with HER2-positive status and the efficacy of HER2/neu targeted therapy in ICCs.