CXCL13 and neoplasm: Two groups of BALB/c mice were simultaneously inoculated on both sides with different tumor cells: the first group was injected on the left back with 4T1-CXCL13-2 cells, and on the right with parental 4T1 cell; the second group was injected on the left back with 4T1-pCDH cells, and on the right with parental 4T1 cells.