BECs (3.6% of COVID-19 patient liver nuclei, Supplement) expressed the lineage markers CFTR, KRT7, and KRT19, and spanned a broad spectrum, partitioning to six main subsets (Fig. 4c): two subsets of differentiated cholangiocytes (BEC1, 2), three of reactive cholangiocytes/HPCs (BEC4,5,6), and one minor subset of cholangiocyte with mesenchymal features (BEC7). The gene discussed is CFTR; the disease is COVID-19.