CCL2 and rhabdomyosarcoma: For example, in a model of metastatic rhabdomyosarcoma, we previously demonstrated that exposure to irradiation [4,6,7] or chemotherapy [6-8] of several organs upregulates the levels of chemokines and growth factors, such as SDF-1, HGF/SF, VEGF, and MCP-1, in addition to bioactive lipids such as S1P, C1P, LPA, and LPC, which are endowed with strong chemotactic activities with respect to normal as well as malignant cells [3,6,7].