CXCL12 and neoplasm: NOX-A12, a Spiegelmer developed by Noxxon Pharma® (Berlin, Germany) is a 45 nt-long aptamer that blocks the stroma cell-derived factor (SDF-1) or also known as CXCL12, a chemokine which promotes stem cell migration to the bone marrow enabling vasculogenesis, tumor growth, and metastasis [45,46].