KRAS and cholangiocarcinoma: Somatic alterations consistent with sporadic cholangiocarcinoma: oncogenic KRAS c.35G>A (p.Gly12Asp);  TP53:c.329G>T (p.Arg110Leu); Single copy deletion of ARID1A at 1p36.11; Single copy deletion of TP53 at 17p13.1; Tumor is likely sporadic, no germline driven LOH