Figure 2 Oesophageal epithelial proliferation assessed by proliferating cell nuclear antigen (PCNA) staining. There were few PCNA positive cells in the normal oesophagus (A) while most epithelial cells of the basal layer and some inflammatory cells exhibited a reaction for PCNA on day 21 after induction of oesophagitis (B). The PCNA labelling index was significantly higher in oesophagitis than in normal oesophagus (C). Values are mean (SD) of six experiments.***?p <0.0001 versus normal oesophagus.