Furthermore, PAPP-A knockout mice showed resistance to atherosclerotic plaque progression, resistance to visceral obesity while on a high-fat diet, delayed thymic involution with persistence of a youthful T-cell phenotype in aged mice, prevention of sarcopenia with age, enhanced insulin sensitivity, and resistance to bleomycin-induced pulmonary fibrosis (4). This evidence concerns the gene PAPPA and pulmonary fibrosis.