SIRT1 and neoplasm: While the role of AMPK in DR has not been tested yet, the histone deacetylases Rpd3 and Sir2, and the tumor suppressors Dmp53 and Tsc2, a member of the TOR pathway, have all been shown to be necessary for lifespan extension in different methods of DR in flies (Rogina et al., 2002; Kapahi et al., 2004; Rogina & Helfand, 2004; Bauer et al., 2005).