 By integrating these models CompuCell3D enables modeling of cellular reactions to external chemical fields such as secretion or resorption, and responses such as chemotaxis and haptotaxis.CompuCell3D is conducive for experimentation and testing biological models by providing a flexible and extensible package, with many different levels of control.High-level steering is possible through CompuCellPlayer, an interactive GUI built upon Qt threads which execute in parallel with the computational back end.