Albrecht T, Rausch M, Roessler S, et al. - This research was attempted to evaluate the proportion of human epidermal growth factor receptor 2 (HER2) positivity and its clinical implications in a large and well-characterized European gallbladder carcinoma (GBC) cohort. Researchers ascertained HER2 status in 186 cases of surgically resected gallbladder adenocarcinoma and a subset of coexistent high-grade biliary intraepithelial neoplasia (BilIN, n = 74) in accordance with the up-to-date consensus for HER2 testing in gastric cancer by immunohistochemistry and dual-color chromogenic in situ hybridization. This study's findings demonstrate a low prevalence of HER2 positivity and indicate HER2 gene amplification as an early, potentially driving event in gallbladder carcinogenesis. Prospective standardized HER2 testing and randomized control studies are required to prove clinical effectiveness of targeted HER2 inhibition in GBC.