1. Department of Biological Sciences, The University of Iowa, Iowa City, IA 52242, USA
2. Department of Biochemistry, Room 641 Botterell Hall, Queen's University, Kingston, Ontario, K7L 3N6, Canada
3. Department of Pathology, Division of Cancer Biology and Genetics, Room A309 Botterell Hall, Queen's University Cancer Research Institute, Kingston, Ontario, K7L 3N6, Canada
4. Laboratory of Cell Adhesion and Metastasis, Mayo Clinic, Griffin Cancer Research Building, 4500 San Pablo Road, Jacksonville, FL 32224, USA