CCR6 and melanoma: Our data also showed that CCR6+CD8+ T cells with the characteristics of early effector memory cells [61] were increased in tumor after vvDD-IL-9 treatment, suggesting that IL-9 might promote CCL20/CCR6-dependent recruitment of CCR6+CD8+ T cells into tumor beds, in agreement with the phenomena previously described in a lung metastatic B16 melanoma model [19].