The clinical development of novel immune and stem cell therapies calls for suitable methods that can follow the fate of cells non-invasively in humans at high resolution. The Bulte Lab has pioneered methods to label cells magnetically (using tiny superparamagnetic iron oxide nanoparticles) in order to make them visible by MR imaging. While the lab is doing basic bench-type research, there is a strong interaction with the clinical interventional radiology and oncology groups in order to bring the methodologies into the clinic.