TNFSF4 and neoplasm: ,9 In an attempt to overcome this disadvantage and to increase the anti-tumor immune response induced by OVs, we developed a conditionally replicating oncolytic adenovirus (OAd) armed with two immune-activating ligands: the ligand for cluster of differentiation 40 (CD40L) and the ligand for tumor necrosis factor receptor superfamily member 4 (OX40L).