Cancer cells of the pleura, by different mutations have acquired the ability to proliferate, invade the surrounding tissues and to metastasize at a distance. Whether or not these operations are actually realized, also depends on the resistance and the collaboration of the surrounding fibroblasts and surrounding cells of the connective tissue. This tumor-associated fibroblasts transmit and receive signals. We want to use this communication to capture freely circulating cancer cells. Then the captured cells can be removed or destroyed. We do this by using spherical microgels having a surface that consists of an adhesive matrix of fibroblasts. We will investigate to what extent controlled experiments fibroblastbevattende microgels can catch the circulating cells mesothelioma (cancer of the pleura).