ERBB2 and neoplasm: Specifically, tumor profiling studies have reported that nearly 40% of BTCs harbor potentially actionable aberrations, among which are isocitrate dehydrogenase (IDH) 1/2 mutations (10%), fibroblast growth factor receptor (FGFR) fusions (10%), HER2 amplifications/mutations (10−15%), BRAFV600E mutation (3%), BRCA2 mutations (3%), and microsatellite instability (1%) [8,9].