Immunohistochemistry revealed a significant higher percentage of CTGF-positive respiratory epithelial cells (staining intensity ≥ 1+) in both end-stage BOS and RAS lungs (median: 77.81% [60.73-90.52], and median: 95.53%, [75.05-98.84]; respectively), compared to control lungs (median: 30.34%, [12.55-37.75], p<0.0001); while there was no significant difference between BOS and RAS (p=0.47) (Figure 2 and comparison of different staining intensities is provided in Table S4). Here, CCN2 is linked to Buschke-Ollendorff syndrome.