<prompt> All of the following factors stimulate angiogenesis in a fetus, except:Vascular Endothelial Growth Factor VEGFBasic Fibroblast Growth Factor bFGFInterleukin - 8 IL8Interferon Alpha INFa  <response>: Interferon Alpha INFa were the first described endogenous inhibitors of angiogenesis, they are anti angiogenic agent. It action is by down regulation of bFGF b Fibroblast Growth Factor. Thus INFa is used in the treatment of pulmonary, brain and other hemangiomas, angioblastomas and giant cell tumours, all of which produce high levels of bFGF. Ref: Tumour Angiogenesis: Basic Mechanisms and Cancer Therapy By Dieter Marme Norbe Fusening, Page 223; Harrisons Principle of Internal Medicine, 16th Edition, Page 463 