1. Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
2. The Ronald O. Perelman Department of Dermatology and the Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
3. BCMB (Biochemistry, Cell, and Molecular Biology) Allied Program, Weill Cornell Medical College, 1300 York Avenue, New York, NY 10065, USA.
4. Cell Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.