CD63 and granulomatosis with polyangiitis: In accordance with these findings, LDGs in our GPA patients were characterized by significantly decreased expression levels of the maturity marker CD10 and increased levels of the activation marker CD66b, while displaying normal expression levels of markers associated with immaturity (CD33), activation (CD16), adhesion (CD62L) and degranulation (CD63), emphasizing the unique nature of LDGs in GPA.