PF4 and interstitial lung disease: To further explore the relationship between the change in CXCL4 and the course of the FVC, a mixed-effects model was generated and the results demonstrated that the change in CXCL4 from baseline to 12 months was associated with the course of the FVC (as a continuous variable) from 12 to 24 months (estimate −1.232; 95% CI −2.405, −0.060; P = 0.040), after controlling for treatment arm assignment, a time trend, baseline quantitative extent of ILD/fibrosis, and baseline FVC.