B16 melanoma cells were injected subcutaneously [5×105 tumor cells in 0.1 ml Phosphate buffered saline(PBS)/animal] using a 27 G needle into the right-lower flanks of the carrier mice as previously described [54]. The body weights and tumor volumes of the animals were monitored twice weekly. The tumor volumes were measured with Vernier calipers and calculated using the following formula: (A×B2)/2, where A is the larger and B is the smaller of the two dimensions. At the end of the experiment, the animals were sacrificed. The tumors were separated from the surrounding muscles and dermis.