1. The Haemostasis and Thrombosis Research Unit, University Hospital Leiden, The Netherlands
2. The Laboratoire Central d’Hématologie (Head: Prof. M. Samama), Hôtel Dieu, Paris, France
3. The Regional Hospital “West-Friesland”, Hoorn, The Netherlands
4. The TNO: Gaubius Institute for Cardiovascular Research, Leiden, The Netherlands