PRTN3 and granulomatosis with polyangiitis: Moreover, we and others have shown that membrane expression of PR3 on apoptotic cells induced a pro-inflammatory response in macrophages and impaired their anti-inflammatory reprogramming following efferocytosis, indicating the impact of PR3 to alter the immunosuppressive effect of apoptotic cell efferocytosis and to promote sustained inflammation in GPA (35, 36).