ZMPSTE24 and progeroid syndrome: Thus, treatment of Zmpste24−/− mice (a progeria mouse model with low DNA repair capacity) with CQ given in 0.9% saline twice per week at 3.5 mg/kg body weight for about 3 months, activates Ataxia telangiectasia mutated (ATM), a serine/threonine protein kinase, a key regulator of DNA damage response, promotes DNA damage clearance, ameliorates premature aging and extends lifespan by 19% [54].