A 68 years old, PR3-ANCA positive, male was initially diagnosed with non-organ threatening GPA based on the ACR 1900 criteria: typical sinus changes, nasal strands (Figure 1A), lung infiltrations in HR-CT, and polyneuropathy, cANCA 1455 CU (range: 0–19 CU). Here, PRTN3 is linked to granulomatosis with polyangiitis.