1. State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, 54 South Xianlie Road, Guangzhou 510060, People's Republic of China.
2. Department of Oncology, Laboratory of Angiogenesis and Vascular Metabolism, Katholieke Universiteit (KU) Leuven, Leuven, B-3000, Belgium.
3. Laboratory of Angiogenesis and Vascular Metabolism, Center for Cancer Biology, Vlaams Instituut voor Biotechnologie (VIB), B-3000 Leuven, Belgium.