library_construction_protocol: Primary human fetal tissue was obtained from patients undergoing elective terminations (REC-96/085) in the first trimester. The liver was dissected from the abdominal cavity and placed into a solution containing Hanks Buffered Saline Solution (HBSS) supplemented with 1.07 Wünsch units/ml Liberase DH (Roche Applied Science) and 70U/ml Hyaluronidase (Sigma-Aldrich), and placed on a microplate shaker at 37oC, 750rpm, for 15 minutes. The sample was subsequently washed three times in HBSS using centrifugation at 400g for five minutes each time. The single cell suspension could then be sorted for EPCAM/CD326 positive cells using CD326 microbeads (Miltenyi), according to the manufacturer's guidelines. The single cell suspension was resuspended in the hepatoblast organoid media (HO-M) for liver samples, or cholangiocyte organoid media (CO-M) for FBO.  The single cell suspension was resuspended in the hepatoblast organoid media (HO-M) for liver samples, or cholangiocyte organoid media (CO-M) for fetal biliary organoids. 7d treatments for both. - TGFb 3.5ng/ml and - Hepatozyme medium (100% - thremofisher scientific - cat 17705021) plus Oncostatin-M 20ng/ml Conversion was performed following the 10X protocol (https://www.10xgenomics.com/) Chromium™ Single Cell 3' Library & Gel Bead Kit v2, 16 rxns PN-120237 Chromium™ Single Cell 3' Library & Gel Bead Kit v2, 16 rxns PN-120237