MET and cholangiocarcinoma: The mesenchymal-epithelial transition factor (c-MET) is a receptor tyrosine kinase that activates multiple downstream signaling pathways upon hepatocyte growth factor (HGF) ligand binding and dimerization including phosphatidyl inositol 3-kinase (PI3K)/AKT, mitogen activated protein kinase and others.17MET gene amplification has been found to be oncogenic and potentially targetable in several solid tumor types including 2% of iCCA cases.16 However, there is limited clinical evidence for c-MET inhibition in MET amplified CCA patients.