The IPF-LFs used in this study were derived from five separate IPF patients and exhibit a senescence-like phenotype, as shown by the increased expression and/or levels of p21, nuclear H2AXγ, IL-6 and IL-8 when compared with Ctrl-LFs (n = 5) (Figure 4a–g). Here, IL6 is linked to idiopathic pulmonary fibrosis.