In line with this, APRIL or TNFSF13 is produced and/or secreted locally by neutrophils, macrophages, and MGC in granulomas of GPA and could promote B and plasma cell survival, of which the latter are found in both respiratory tract and kidney tissue of AAV [22,74,75,152]. This evidence concerns the gene TNFSF13 and granulomatosis with polyangiitis.