To investigate whether CXCL13 could mediate tumor growth inhibition in immunodeficient mice, BALB/cA-nu nude mice with thymus and T-lymphocyte deficiency were inoculated s.c. with 4T1, 4T1-pCDH, 4T1-CXCL13-1, or 4T1-CXCL13-2 tumor cells. This evidence concerns the gene CXCL13 and Nezelof syndrome.