IDH1 mutations, FGFR2 fusions, MSI-H, NTRK fusions, BRAFV600E mutations and ERBB2 (HER2) have been classified as level I and three other aberrations as level III according to the most recent ESMO Guideline for Biliary Tract Cancer (Table 1) (16). This evidence concerns the gene ERBB2 and biliary tract neoplasm.