Figure 1. Aging-related markers are significantly overexpressed in the lung tissues of IPF patients. Human lung tissues of IPF (n = 12) and age-matched normal lung tissues (n = 12) were analyzed. (A) Representative images of HE staining of lung tissues (original magnification, 100×). (B) Representative images of the aging-related marker, P21WAF1, via IHC staining of lung tissues (original magnification, 100× in control and 200× in IPF). (C) Representative results of SA-β-Gal staining of lung tissues (original magnification, 100×). (D) Enlarged images of SA-β-Gal staining (200×). (E) Immunofluorescence staining of SP-C (an AEC2-specific marker, red) and P21WAF1(green) was conducted to confirm senescent marker expression in AECs (original magnification, 400×). (F, G) P21WAF1 senescent marker in lung tissues was measured by western blotting. Each dot represents an individual lung tissue. **p < 0.01. Unpaired, two-tailed Student’s t test.