We have previously reported that the single-time-point baseline (pre-treatment) plasma level of mucin-1/KL-6 is also prognostic and may serve as a clinical predictor of important unfavorable outcomes (specifically, drug-related hepatitis, on-treatment AE-IPF, and all-cause mortality) among patients with IPF receiving nintedanib [43]. Here, MUC1 is linked to idiopathic pulmonary fibrosis.