liv-2 was identified in screens for animals with increased stress resistance and longevity; liv-2 is defined by a single mutation that results in animals that are long-lived (Age), dye-filling defective, form dauers constitutively at high temperature (Daf-c), and display increased thermotolerance; the liv-2 Age and Daf-c phenotypes can be suppressed by a mutation in daf-16, suggesting that liv-2 functions upstream of daf-16 in regulating lifespan and dauer formation.