1. Philadelphia College of Osteopathic Medicine, Department of Biochemistry/Molecular Biology, 4170 City Avenue, Philadelphia, PA 19131, U.S.A.
2. SmithKline Beecham, King of Prussia, PA 19406, U.S.A.
3. Thomas Jefferson University, The Cardeza Foundation for Hematologic Research, Philadelphia, PA 19107, U.S.A.