In a study by Marcin Komorowski and colleagues, expression of C-X-C motif chemokine receptor 4 (CXCR4) antagonists from an oncolytic vaccinia virus significantly enhanced the therapeutic efficacy of dendritic cell (DC) vaccines compared to either a soluble CXCR4 antagonist or oncolysis alone, when administered intravenously to mice bearing neuroblastoma tumors. The gene discussed is CXCR4; the disease is neuroblastoma.