This application is a request for partial support of the International Conference on Molecular Systems Biology: Gene Circuitry, Dynamical Control in Biology and Medicine, and Biomedical Software Development and Integration (ICMSB'04), which will be held 21-25 August of 2004 at the Granlibakken Conference Center in Tahoe City, California. This workshop-style conference is the continuation of seven biennial meetings that have traditionally concentrated on advances in molecular systems biology achieved through systems theory, software development, and applications to biological systems. The emphasis typically has been on systems at the molecular level and their relationship to systems at higher levels of organization. At the 2004 meeting, we intend to continue this tradition while encouraging contributions from young investigators, specifically advanced graduate students, postdoctoral fellows, and junior faculty. As in past meetings, we will welcome contributions covering a spectrum of theory, methods and applications, in addition to those focused on the themes of the conference. The themes for 2004 will address three timely subjects: gene circuitry, dynamical control in biology and medicine, and biomedical software development and integration. The flood of data provided by high-throughput technologies that have grown out of the genome projects and the proliferation of software tools for analyzing these data have revealed pressing needs for integration and multidisciplinary approaches to address new problems of biological complexity. Like previous meetings, this conference is intended to attract researchers from a broad range of disciplines--particularly computer science, engineering, mathematics, physics, biochemistry, genetics, microbiology, and physiology--with expertise relevant to these problems. The common thread will be a strong interest in improving our understanding of complex biological systems through the application of quantitative methodologies. Approximately 100 individuals will be participating; there will be approximately 25-30 speakers, 20-30 poster presentations, and 6-10 software demonstrations. Contributions are accepted based on peer review by a 14-member Scientific Committee. Selected papers will be proposed for further review and, if accepted, subsequent publication in a special issue of Mathematical Biosciences. ? ?