Gene expression of Wnt and Notch signalling components is enhanced in HPC niches during disease. Examples of cryosections (6 μm) of normal liver and lobular dissecting hepatitis immunostained for Keratin 7 (A), a marker of HPCs and cholangiocytes. The red lines indicate the quiescent HPC niche in the periportal area of normal tissue and the activated HPC niche throughout the parenchyma of diseased tissue (A). These areas were specifically selected by means of laser microdissection for RNA isolation and gene expression analysis. Relative gene-expression for components of Wnt (B), and Notch (C) signalling pathways show upregulation of these pathways in HPC niches during disease. FZD1, Frizzled 1; TCF3, transcription factor 3; AXIN2, axis inhibitor 2; JAG, jagged; HEY1, hairy/enhancer of split-related with YRPW motif; N.S., not significant; N/D, not detectable.