We are using a variety of functional in vitro assays to measure different tumor-cell specific characteristics in cell culture. For example, to test the ability of tumor cells to invade and migrate, a chemotactic gradient can be used. In addition, determining how long cells need to close a preformed gap the capacity to migrate can be assessed. In an apoptosis assay, cell death is induced to determine basal and induced apoptosis. Here, cell death is measured by the amount of resulting fluorescent product. In a colony formation assay a low number of cells is seeded and observed over a period of time. It may provide details about a cells capacity to form colonies, the colony morphology and the interactions of the cells involved.