The selected anti-PD-L1-scFv binds to PD-L1 thus interfering in PD-1 and B7.1 interactions, representing the principal PD-L1 receptors on immune cells, and does not interfere with the ability of Ad5Δ24 to induce cell death in an in vitro model of melanoma, actually enhancing it. This evidence concerns the gene CD80 and melanoma.