FLI1 and erythroleukemia: For 20 years, Fli1 was viewed as a member of the ETS transcription factor family originally identified in erythroleukemia induced by the Friend Murine leukemia virus [30,31,32], but recent evidence indicates that Fli1 is a master of transcription factor which promotes vascular morphogenesis and angiogenesis [33,34,35].