1. McMaster University, Hamilton, Ontario L8N 3Z5, Canada.
2. Genentech Inc., South San Francisco, CA 94080, USA.
3. Institut Universitaire de Cardiologie et de Pneumologie de Québec, Québec, Québec G1V 4G5, Canada.
4. University of British Columbia, Vancouver, British Columbia V5Z 1M9, Canada.
5. University of Saskatchewan, Saskatoon, Saskatchewan S7N 0W8, Canada.
6. University of Calgary, Calgary, Alberta T2N 4Z6, Canada.
7. Karolinska University Hospital, Stockholm S-141 86, Sweden.
8. University of Alberta, Edmonton, Alberta T6G 2G3, Canada.