CXCL13 was initially described as a chemokine highly expressed in the follicles of Peyer's patches, spleen, and lymph nodes and as a strong chomoattractant for B cells. CXCL13 is expressed by T follicular helper cells, dendritic cells, and stromal cells in B cell areas of secondary lymphoid tissue. CXCR5, the receptor for CXCL13, was initially cloned from Burkitt’s lymphoma cells and named BLR1. CXCR5 is highly expressed in those cells and B cells. CXCL13, CCL19, and CCL21 are involved in the formation of tertiary lymphoid tissues in chronic antigen-induced arthritis. CXCL13 takes part in the allergic airway inflammatory process. In addition, high expression of CXCL13 has been linked to lupus, Helicobacter pylori-associated gastritis, multiple sclerosis, and rheumatoid arthritis. In summary, CXCL13 is highly expressed at the sites of new lymphoid tissue formation in a variety of chronic inflammatory conditions.