Michael Blinov University of Connecticut Health Center Title: Bringing rule-based modeling to VCell users Abstract: We are implementing the rule-based approach into the VCell modeling and simulation framework. By combining a reaction network specified in the VCell editor (explicitly specifying individual species and reactions) with multi-component species and rules of interactions, a user is able to use rule-based specifications within the familiar “look and feel” environment of the VCell reaction editor. The new VCell interface includes dual views for a reaction network: a set of tables describing all model elements, and a bipartite graph with species and reaction nodes. Both views are extended to support rule-based features.