CXCR4 and neoplasm: This was an unexpected result as MTLn3 CXCR4 cells were more efficient in leaving the primary tumor and entering the bloodstream compared with MTLn3 JP cells, thus we looked for metastasis formation in the bone and lymph nodes but no difference was observed at these sites (P = 0.7 and P = 0.8, respectively) [see Additional data file 10].