EGFR and cholangiocarcinoma: Genomic analyses of CCA revealed several mutations, e.g. of the isocitrate dehydrogenase (IDH) 1 and 2 genes, the transformation-related protein 53 (p53) gene and the Kirsten rat sarcoma virus (KRAS) gene as well as an amplification of the epidermal growth factor receptor (EGFR) gene and of the fibroblast growth factors (FGFR) 2 gene, which opens up the possibility of targeted drug therapy [26, 40–42].