Modern recombinant DNA technology offers fascinating methods to study the physiology and pathophysiology of the liver and is already widely used in various fields of liver research. The present review is intended to summarize the major progress that has been achieved in the past year using methods of molecular biology. Molecular biology is extremely important in a wide range of clinical conditions (eg, carcinogenesis, toxic and infectious diseases, and genetic disorders) and advances obtained by recombinant DNA technology provide the rational basis for gene therapy in the liver, which is an attractive target organ for the treatment of genetic and acquired disorders. Because some topics are reviewed elsewhere in this issue and owing, to space limitations, we concentrate on three pathophysiologic settings that are to some extent related to each other: the acute-phase reaction, hepatic fibrogenesis, and liver regeneration. After a brief introduction, the area of interest, in particular insights achieved by recombinant DNA technology, is discussed in more detail.