CCL20 and neoplasm: At the mechanistical level, the anti-tumor activity of Th17 cells is likely to be related to the recruitment of effector cells, such as Th1, CD8+ cells, NK cells, or dendritic cells within the tumor micro-environment, through increased secretion of CXCL9, CXCL10, and CCL20 [123,135,136], and/or the negative presence of Tregs [114].