TP53 and pulmonary fibrosis: Together, these results indicate that Tert expression in the lungs of adult mice with pulmonary fibrosis is sufficient to decrease DNA damage and apoptosis, as well as to decrease the levels of p21 and p53, as early as 3 weeks after viral treatment and this is maintained until the end-point of the experiment at 8 weeks post-viral treatment when the fibrosis was reverted or cured in a significant proportion of mice treated with telomerase.