These findings are consistent with the effects of DR on the growth of early tumors due to both systemic changes in the host (e.g., circulating levels of insulin or IGF-1) and signaling events that are intrinsic to the tumor cells (e.g., those involving AMPK, mTOR, or SIRT1, all of which interact with the PI3K pathway at multiple levels). The gene discussed is SIRT1; the disease is neoplasm.