 CCL20 is expressed in several tissues with highest expression observed in peripheral blood lymphocytes, lymph nodes, liver, appendix, and fetal lung and lower levels in thymus, testis, prostate and gut.The gene for CCL20 ("scya20") is located on chromosome 2 in humans.Recent research  in an animal model of multiple sclerosis known as experimental autoimmune encephalitis (EAE) demonstrated that regional neural activation can create "gates" for pathogenic CD4+ T cells to enter the CNS by increasing CCL20 expression, especially at L5.