1. Retina Research InstituteMassachusetts Eye and Ear Infirmary, Harvard Medical School 234 Charles Street Boston MA 02114 USA
2. Department of Vitreoretinal SurgeryCenter for Ophthalmology and Center for Molecular Medicine (ZMMK), University of Köln Joseph Stelzmann Str. 9 D‐50931 Köln Germany
3. Surgical Research LaboratoriesChildren's Hospital, Harvard Medical School Boston MA 02115 USA
4. Dana‐Farber Cancer InstituteHarvard Medical School Boston MA 02115 USA
5. Beetham Eye InstituteJoslin Diabetes Center Boston MA 02115 USA
6. Department of OphthalmologyHarvard Medical School Boston MA 02115 USA