Leen focuses primarily on Belgian and European competition law, State aid, and the law of the EU Internal Market.
She has been a Senior Attorney at Eubelius and a member of the Brussels Bar since January 2001.
Leen holds a degree in law from the University of Ghent (1996) and obtained the "Diplôme d'études supérieures specialisées (DESS) en droit de l'Union européenne" from the Paris XI University.
Leen is also a teaching assistant in the Ghent European Law Institute at the University of Ghent.
She is the author of several contributions to Belgian and European law journals.