Firstly, in terms of ILD, among patients with AAV, it has been reported that ILD occurs in 13–14% of patients with AAV and 20% of MPO-ANCA-positive patients, a UPI pattern is observed in most cases (up to 75%), and the fibrotic type of ILD is significantly associated with a worse outcome, particularly an increase in the rate of all-cause mortality [38,39,40,41]. The gene discussed is MPO; the disease is interstitial lung disease.