In the present study cellular p53 content determined by IHC was overexpressed in 77% of CCA tissue samples compared to match NT tissue, suggestive of carriage of (putative) mutant p53. Furthermore, 37-97% of mRNA levels of seven p53 target genes were down-regulated in CCA tissues compared to those in matched adjacent NT specimens, while only 23% of p53 mRNA was down-regulated. The gene discussed is TP53; the disease is cholangiocarcinoma.