Murine CXCL13 chemoattracts B cells and is one of the key players for B cell entry into lymphoid follicles. It takes part in the formation of ectopic lymphoid follicles. Murine CXCL13 chemoattracts B cells and is one of the key cytokines for B cell entry to lymphoid follicles. It takes part in the formation of ectopic lymphoid tissue in chronic inflammation, and elicits its functions primarily by interacting with its chemokine receptor, CXCR5.