CXCR4 and neoplasm: Out of 13 mice implanted with N91-CXCR4-14 cells, 12 developed a tumour, with a mean volume of 1390 mm3 at 49 days, whereas in the control group, 8/8 developed a tumour, reaching a mean volume of 15 mm3 after 49 days (Figure 2c).