The ROC curves for TSLP and IL-33 demonstrated a clear difference between the IPF and NC groups (TSLP: AUC = 0.655; IL33: AUC = 0.706) (Fig. 2a and b), as well as among the patients with IPF and those with other interstitial lung diseases (n = 61, TSLP: AUC = 0.786, and IL-33: AUC = 0.781) (Fig. 2c and d). Here, IL33 is linked to idiopathic interstitial pneumonia.