CCR6 and granulomatosis with polyangiitis: To investigate the extent to which the chemokine receptors CCR4 and CCR6 could be implicated in T-cell recruitment in GPA, we analyzed CCR4 and CCR6 expression on circulating T cells, assigned CCR4- and CCR6-expressing cells to the respective memory cell subsets, and determined the cytokine production of CCR4+ and CCR6+ T cells.