Genetic analysis reveals that DAF-16 is required for daf-2 -dependent lifespan extension and dauer formation. When not phosphorylated, DAF-16 is active and present in the nucleus . [ edit ] Factors influencing the levels in the circulation [IMG]file:///C:/DOCUME%7E1/Alex/LOCALS%7E1/Temp/msohtmlclip1/01/clip_image009.gif[/IMG] [IMG]file:///C:/DOCUME%7E1/Alex/LOCALS%7E1/Temp/msohtmlclip1/01/clip_image010.gif[/IMG] 3-d model of IGF-1 Factors that are known to cause variation in