Animal cell technology has been making tremendous progress. Originally this term reminded people of engineering for high density and large volume culture of animal cells. At present many fields of biological sciences are aiming at advance in animal cell technology. Cell culture engineering is aided not only with developments in apparatus, matrix, media, and computational analysis, but also with new biological procedures in gene and protein technology, cell biological resources and immunological methods. Results obtained with animal cell technology are applied to production of pharmaceuticals, diagnosis reagents and food endowed with physiological functions, and cell and gene therapy of animals and humans, and useful for elucidating scientific phenomena. It is also essential to establish methods of evaluation for functionality and safety of newly discovered molecules and cells. The progress in animal cell technology is supported by, and attributes in both of basic and applied sciences. The proceedings of the Fifth International Meeting of the Japanese Association for Animal Cell Technology (JAACT) covers the subjects above mentioned. The articles in this book will help researchers in many fields to understand the current status and future trends in animal cell technology. JAACT organized this Meeting and we express our gratitude to the members of JAACT. We gratefully acknowledge all the members of the organizing committee for their dedication in assuring the Meeting's success. For their valuable supports, we also thank the Japanese Biolndustry Association and Saitama Foundation for Culture and Industry.