Models of tumors are used in biomedical research to understand their complex behavior in humans. Recent biomimetic devices beyond the classical 2D cultures are microfluidic chips or 3D printed tumor organoids. We use mathematical models in combination with data from these biomedical models provided by our collaborators to better understand processes occurring in the glioblastoma microenvironment. Specifically, we can develop hypotheses in-silico, verify them in the biomimetic devices and make proposals that could subsequently move into clinical practice.