Considering that a lack of caveolin-1prevented both premature senescence of lung fibroblasts and development ofpulmonary emphysema, we propose a model in which oxidants contained incigarette smoke induce premature senescence of lung fibroblasts in acaveolin-1/ATM/p53-dependent manner and that senescent lung fibroblastscontribute to the pathogenesis of pulmonary emphysema. This evidence concerns the gene ATM and pulmonary emphysema.