Dr. Marcel J.M. Schaaf is Associate Professor at the Institute of Biology Leiden (IBL), at Leiden University. His research focuses on the mechanism of action of glucocorticoids, both natural glucocorticoid hormones such as cortisol which play an important role in our diurnal rhythmicity, and synthetic analogs of this hormone such as dexametahsone and prednisolone which are widely used clinically as anti-inflammatory drugs. In this research, he predominantly uses the zebrafish as a model system and advanced microscopy techniques to study this model.