The evidence from previous and current studies shows TERT is transiently induced in this lung fibrosis model during day 7–14 after BLM treatment [4, 49], which precedes the peak of α-SMA expression or myofibroblast differentiation that is typically seen on 21 days post BLM treatment [4, 50].Thus the inhibitory effect of TERT deficiency in mesenchymal cell proliferation, survival and persistence may lead to less severe fibrosis in TERT CKO mice. This evidence concerns the gene ACTA1 and pulmonary fibrosis.