To investigate the influence of the MUC5B promoter polymorphism on CLAD/graft loss, 568 patients transplanted for a chronic end-stage respiratory disease between 2004 and 2015 were included: 117 (20.6%) patients had any form of ILD, 307 (54.0%) COPD/emphysema, 105 (18.5%) CF/BRECT, 37 (6.5%) PHT and 2 (0.4%) another diagnosis. This evidence concerns the gene MUC5B and pulmonary hypertension, primary, 1.