Diethylnitrosamine (DEN) induces irreversible hepatocellular carcinogenesis through overexpression of G1/S-phase regulatory proteins in rat.

Hepatocellular carcinoma (HCC) is the fifth most frequent cause of cancer deaths in males and was the third most frequent cause of cancer deaths in 2007 throughout the world. The incidence rate is 2-3 times higher in developing countries than in developed countries. Animal models have enabled study of the mechanism of HCC and the development of possible strategies for treatment.