CXCR4 and neoplasm: To assess the anti-tumor response of CXCR4 in combination with anti-OX40, tumor-bearing mice were treated with anti-OX40 antibody (1 mg/kg twice weekly) and/or CXCR4 antagonist (BL-8040; 4 doses; 24 h apart; 20 mg/kg) in the presence of tumor-specific antigen priming (E7-peptide; 3 doses/ one week apart).