"European Centres of Expertise Networks for rare diseases have been identified by the European Commission as one important area of future activity in the attempt of achieving one of the main objectives across the EC endeavour of “Optimising the delivery of health care to European Citizens”. It is obvious that especially in rare diseases the joined forces of the experts networking throughout Europe are more likely than national services to meet the needs and expectations of patients. The construction and implementation of European networks of centres of expertise (ENCE) call for input from many different stakeholders: patients and doctors and other care team members, clinical researchers, health administration, and health insurers will have to be heard to come to a model of such networks that can easily be used as blueprint for most of the rare disorders. To achieve this goal first a mapping exercise of existing networks and elements needed for such networking has to be done. We plan to do so for three different rare entities, i.e. cystic fibrosis (CF), pulmonary lymphangioleiomyomatosis (LAM), and lung transplantation (LTX), having in common that they all comply with the EC definition of a rare disease. From the information gathered during this process the areas of activity and a detailed set of criteria for such European networks will be developed. These construction principles will be brought together in a blueprint to be used for other rare disorders. These criteria can then be used for certification, quality control, and funding of a European system of networks. Networking in this European sense will make the best possible use of resources already existing and remaining in the responsibility of the individual member states by interfacing and complementing these present and future elements. This will help the health care system partners to learn from the best and improve the quality of care to the best European level of expertise."