CXCL12 and neoplasm: Interestingly, although not in the context of bone metastasis, treatment with an oncolytic vaccinia virus targeting CXCR4 resulted in destruction of tumor vasculature concomitant with decreased levels of CXCL12 and VEGF within the 4T1 tumor mass, which overall resulted in increased tumor-free survival and decreased formation of metastases in a murine model [299].