Even if we excluded patients with on-treatment AE-IPF from this analysis, we observed similar trends in pulmonary function decline, in addition to a nonsignificant pattern of a faster annual decrease in DLCO, in patients with KL-6 ≥ 2.5 ng/mL (Fig. 4c, d, and the right half of Fig. 4e, f). Here, MUC1 is linked to idiopathic pulmonary fibrosis.