We did evaluate whether any of the progressor clusters could be explained by other clinical and radiological variables collected during the COMET study, including progression metric (e.g. through AE-IPF or a > 10% drop in FVC, etc.), smoking status, each participant’s genotyping at the MUC5B rs35705950 and the TOLLIP rs5743890 SNPs, and the presence of ground glass and honeycombing in their baseline CT scan. This evidence concerns the gene MUC5B and idiopathic pulmonary fibrosis.