In both groups, reduction of blood CXCL12 was observed at 72 h and 21 days post B16-hCXCR4-GFP cells inoculation (at 72 h CXCL12 was 10.6 ± 0.3 ng/ml in EG -mice and 7.7 ± 1.0 ng/ml in CLG- mice while at 21days CXCL12 was 7.1 ± 1.8 ng/ml and 4.1 ± 2.0 ng/ml respectively, in EG and CLG-mice) suggesting that plasma CXCL12 was not influencing the propensity of tumor cell homing to the lungs/CLG. This evidence concerns the gene CXCL12 and neoplasm.