EPO and cyst: Loss of VHL function due to VHL gene mutation results in the accumulation of HIF, which then induces the over-expression of hypoxia related genes including erythropoietin (Epo) [6], vascular endothelial growth factor (VEGF) [7], [8] and platelet-derived growth factor (PDGF) [9], thus promoting angiogenesis, proliferation and tumorigenesis in multiple organs such as hemangioblastoma in brain and retina, renal cell carcinoma and cyst, pheochromocytoma, pancreatic cyst and tumor.