This award provides partial funding for the workshop, " Spatial effects in signal transduction", which is designed to bring together experimentalists and theorists interested in the spatial effects of signal transduction. The workshop will be held at the Aspen Center for Physics from August 21 until September 11, 2005. The objectives of the workshop are 1) to help identify problems that are suitable for a combined experimental/theoretical approach and 2) to foster future collaborations across disciplinary boundaries.