CXCL12 and neoplasm: Increases in growth factors and cytokines (VEGF, granulocyte-colony stimulating factor and stromal cell-derived factor 1) were also reported following VDA treatment in other tumor models and were shown to induce mobilization of bone marrow-derived cells, including circulating endothelial progenitor cells that colonize the viable tumor rim and contribute to tumor regrowth6,24.