Cover image supplied by S. Ferreira-Gonzalez and S.J. Forbes, MRC Centre for Regenerative Medicine, Edinburgh, UK, who are funded by MRC and Principals Career Development Edinburgh University grants. Immunofluorescence image of ductular reaction in the liver. Tissue was stained to show marker of biliary differentiation keratin 19 (rat anti-troma III) and red fluorescent protein (rabbit anti-RFP). Nuclei were stained by DAPI.