Indeed, we observed that patients with EGPA had elevated serum levels of IL-25, TSLP, and soluble ST2 (sST2), the decoy receptor for IL-33 (Figure 1, A–C), whereas IL-33 was not detected in serum from patients with EGPA or controls (data not shown). Here, IL25 is linked to eosinophilic granulomatosis with polyangiitis.