It is our utmost pleasure to present a new book on tobacco BY-2 cells, Tobacco BY-2 Cells: From Cellular Dynamics to Omics, as the 58th volume in the book series Biotechnology in Agriculture and Forestry (BAF). It represents an ext- sion of the previous book Tobacco BY-2 Cells,vol. 53of the BAF. Moreover, the content is rather different from the latter and includes new topics, gleaned from the First International Symposium on Tobacco BY-2 Cells held at the Plant Science Center of the RIKEN, Yokohama, organized by Nagata, Matsuoka and Inze, in September 2004. To this symposium came more than 200 people from different parts of the world to discuss issues. Although most of the contributors to thepreviousvolumeof Tobacco BY-2 Cells gave talks on their subjects, there were many other speakers who presented new topics and approaches. So we enjoyed the symposium very much. Thus we decided to compile a new volume on tobacco BY-2 cells which includes these new topics. In addition, towards the end of the symposium, our common understanding was that the tobacco BY-2 cell system is still important in plant biology, in particular for studying the dynamic features of plant cells. We hope this volume is useful for plant biologists. Contents of the book are as follows: in Chapters I. 1–I. 6, various aspects of the cell cycle and cellular dynamics using BY-2 cells are described. In Ch- ters II. 1–II.