1. Department of Biological Informatics and Experimental Therapeutics, Graduate School of Medicine, Akita University, 1-1-1 Hondo, Akita, 010-8543, Japan
2. Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institutes of Child Health and Human Development, National Institutes of Health, 35A Convent Drive, Bethesda, MD 20892-3752, USA