Animal cell technology is a growing discipline of cell biology, which aims not only to understand structures, functions, and behaviours of differentiated animal cells but also to ascertain their ability to be used for industrial and medical purposes. The goal of animal cell technology includes accomplishments of clonal expansion of differentiated cells with useful ability, optimisation of their culture conditions, modulation of their ability for production of medically and pharmaceutically important proteins, and the application of animal cells to gene therapy, artificial organs, and functional foods. This volume gives the reader a complete review of the present state of the art in Japan and other countries