Furthermore, given the evidence that patients with KRAS mutations have a poorer response to EGFR-directed therapies [17, 18] and that biliary tract cancers have a spectrum of mutations in EGFR and its downstream signaling pathways, including KRAS and PIK3CA [19–23], we evaluated the potential relationship between mutational status and clinical outcome. The gene discussed is EGFR; the disease is biliary tract neoplasm.