Cut-off values of 3.52 pg/μg TSLP and 3.77 pg/μg IL-33 were shown to differentiate between the IPF and NC groups with 99.2 and 94.3% accuracy (96.7 and 80% specificity, respectively, with 100% sensitivity), while the cut-off values of 4.66 pg/μg TSLP and 2.52 pg/μg IL-33 possessed 99.4 and 93.2% accuracy (98.4 and 90.2% specificity and 100 and 95% sensitivity, respectively) for differentiating the IPF from the other interstitial lung disease groups. Here, IL33 is linked to idiopathic interstitial pneumonia.