PRTN3 and granulomatosis with polyangiitis: Relapse rates reach up to 38% at 5 years in GPA, and PR3-ANCA, which is strongly associated with GPA, acts an independent predictor of relapse.4 However, there is a lack of evidence base guiding treatment of predominant granulomatous inflammation typically seen in localized and early systemic disease and, given the relapsing course of disease over time, much emphasis has been placed on identifying less toxic treatments associated with better patient tolerability and improved clinical efficacy.5,6