CDKN2A and idiopathic pulmonary fibrosis: In IPF tissues, the identification of telomere-associated foci, a sign of unresolved telomere DNA damage, together with the increased expression and co-localization of γH2A.X and the high expression of p16 and p21 in remodeled areas are characteristic hallmarks of cellular senescence [121, 122] (Fig. 3).