In a study of accelerated aging in chronic obstructive pulmonary disease (COPD) that examined interconnected hallmarks of aging [13, 56], the authors determined that both klotho levels and telomere length were decreased among COPD patients compared to controls, which supports the idea that circulating klotho is lower under disease-induced age-accelerating conditions. The gene discussed is KL; the disease is chronic obstructive pulmonary disease.