COL4A5 and Buschke-Ollendorff syndrome: When we stratified our BOS cohort on the basis of a pre-BOS COL4A5 cut-off value of 10.82 pg/ml (< 10.64 pg/ml and > 10.82 pg/ml), we observed that the former group had longer CLAD-free survival than the latter group (p = 0.046) (Fig. 2c).