(From the Bristol Press). A look at early stage research into one gene associated with aging shows what scientists have to go through into order to obtain even the smallest insights: "The gene, called 'lineage defective 4,' or lin-4, encodes a small piece of RNA ... worms lacking the lin-4 gene died prematurely. Extra copies of lin-4 led to shorter lives. Worms with mutated, less effective insulin receptors and mutated lin-4 lived a normal lifespan. C. elegans with normal lin-4 and mutated insulin receptors lived twice as long as normal. This finding suggests that lin-4 influences lifespan through the insulin signaling system ... It also explains why worms, rats and mice placed on low-calorie diets tended to live longer ... Less insulin means less protein synthesis and lower production of damaging chemical by-products ... If humans could somehow gear up their lin-4 genes and make extra [microRNA] to turn down insulin signaling, they might be able to delay aging."