This issue of Genome Informatics contains papers presented at the Twentieth International Conference on Genome Informatics (GIW 2009) held in Yokohama, Japan from December 14th to 16th, 2009.
The first Genome Informatics Workshop (GIW) was held in Tokyo in 1990, the dawn of human genome sequencing. Remarkably, the invited talks by Akiyoshi Wada, Ross Overbeek, and Yoshiyuki Sakaki that year were all on the subject of the computational support for genome sequencing. Since then, GIW has provided unique opportunities to encourage bioinformatics and create bridges between theory and experiments, academia and industry, and East and West. GIW is the longest running international bioinformatics conference.
The 20th International Conference on Genome Informatics (GIW 2009) was held at PACIFICO Yokohama Convention Center, Japan, on December 14-16, 2009. We accepted 18 papers from the 39 submissions. The two best papers were:

  • C. Nelson Hayes, Diego Diez, Nicolas Joannin, Minoru Kanehisa, Mats Wahlgren, Craig E. Wheelock, and Susumu Goto.
    "Tools for investigating mechanisms of antigenic variation: new extensions to varDB."
  • Kouichi Kimura and Asako Koike,
    "Localized suffix array and its application to genome mapping problems for paired-end short reads."
    In addition, this book contains abstracts from the five invited speakers: Sean Eddy, HHMI's Janelia Farm (USA), Minoru Kanehisa, Kyoto University (Japan), Sang Yup Lee, KAIST (Korea), Hideyuki Okano, Keio University, (Japan), and Mark Ragan, University of Queensland (Australia).
    The electronic versions of all these papers in this issue are also freely available from the website of the Japanese Society for Bioinformatics (JSBi)(

    Shinichi Morishita
    Sang Yup Lee
    GIW 2009 Program Committee Co-Chairs

    Yasubumi Sakakibara
    GIW 2009 Conference Chair