Dr. Paul P. Geurink heads the Chemical Biology & Drug Discovery lab at the Leiden University Medical Center (LUMC). He combines high-throughput screening, organic synthesis and chemical biology to develop chemical tools, such as assay reagents, small-molecule inhibitors and activity-based probes, that target the ubiquitin and ISG15 systems. These tools are used to obtain fundamental insights into the role of various enzymes within these systems and to interfere with their biological functioning with the ultimate goal of fighting diseases that are associated with these enzymes.