Notably, lineage tracing revealed that, on postnatal day 10, Alb-Cre was still active in biliary cells and, together with the observation that K19CreERT/+; KrasLSL-G12D; Ptenflox/flox mice gave rise to pre-malignant papillary ductal lesions in periportal areas, these findings suggest that CCA arises from cholangiocytes in these models. The gene discussed is ALB; the disease is cholangiocarcinoma.