PCNA and polyostotic fibrous dysplasia: The role of PCNA is also important since this is a protein involved in synthesis and repair of DNA [44], Venturi et al. showed that PCNA immunostaining in cancerous and surrounding cirrhotic livers was selectively localized in the nucleus and mainly in hepatocytes, with few cases showing weak positivity in fibroblasts and biliocytes [44], very similar to our immunofluorescence findings, in where the PCNA localization was present in the nucleus of liver tissues of CT group, but this response was no affected by PFD treatment.