A study of the cancer-critical genes of C. sinensis-associated CCA showed that PSMD10 and CDK4 genes were upregulated, the tumour suppressor gene p53 and RB protein as well as BAX and caspase 9 were down-regulated, and PCNA was overexpressed in a C. sinensis-induced hamster CCA model [77]. This evidence concerns the gene CDK4 and cholangiocarcinoma.