CCL21 and autoimmune disease: Another study reported elevated levels of lymphotoxin α, lymphotoxin β, CCL21, CXCL12, CXCL13, and CCL22 in the thyroid glands of patients with autoimmune diseases and reported that the percentages of CXCR4+ T cells and CCR7+ B and T cells in the thyroid glands of patients with AITD were significantly lower than those in peripheral blood mononuclear cells (25).