TGFB1 and pulmonary fibrosis: Type II AEC-specific deletion of type II telomere repeat binding factor (TRF)-1—a telomere shelterin protein—in mice resulted in short telomeres [109], increased expressions of p53 and p21 [110], accumulation of SAβGAL-positive senescent cells [109], increased TGF-β1 expression [109], and development of spontaneous lung fibrosis [109,110].