Animal cell technology is a growing discipline of cell biology which aims to understand structures, functions and behaviors of differentiated animal cells, and also to ascertain their abilities to be used in industrial and medical purposes. The goal of animal cell technology includes accomplishments of clonal expansion of differentiated cells with useful ability, optimization of their culture conditions and pharmaceutically important proteins and the application of animal cells to gene therapy, artificial organs and functional foods. This book contains the proceedings of the 17th Annual and International Meeting of the Japanese Association for Animal Cell Technology (JAACT) in Nagoya, Japan, in November 2004. This volume gives the readers a complete review of the present state-of-the-art in Japan and other countries. The Proceedings are useful for cell biologists, biochemists, molecular biologists, immunologists, biochemical engineers and other disciplines related to animal cell culture.