[Studies of physiological functions of cytokines by generating mutant mice through the transgenic and the gene-targeting technology].

Molecular cloning of gene coding for cytokines, growth factors and their receptors have facilitated an accumulation of findings regarding the function of their products. So far, many kinds of functions of such molecules in vitro have been identified. To clarify the physiological roles of such molecules in vivo a variety of cytokine-transgenic mice and a few cytokine-gene targeted mice have been generated. Many of the phenotypes expressed by these animals are as expected from the in vitro assay data, but some are unexpected. In this short article, some of the phenotypes reported are introduced and their significance is discussed.