Numerous somatic alterations were described in CC affecting oncogenes (e.g., KRAS), tumor suppressor genes (TP53, SMAD4), epigenetic factors (IDH1/2), chromatin-modifying genes (e.g., ARID1A, BAP1, ERBB2, FGF2, and PBMR1) [10,11,12,13,14]. The gene discussed is ERBB2; the disease is cholangiocarcinoma.