CCR4 and neoplasm: Notably, the expansion of CCR6/CCR4 double positive cells clearly induced by stimulation with apoptotic cell-loaded IFN-DC (Fig. 7D), correlated with the levels of IL-17 detected in the corresponding culture supernatants (Fig. 7E), indicating the capability of IFN-DC which had phagocytosed apoptotic tumor cells to drive Th17 differentiation.