Following the infection of MUG Mel-1 and MUG Mel-2 cell lines with AdV-24-ICOSL-CD40L and AdV-D24 at the concentration of 100VP/cell, alone and/or in combination with anti PD-1 (pembrolizumab) or only in the presence of pembrolizumab, a reduction in cell viability (expressed in the percentage (%) of viable cells) was observed. Here, ICOSLG is linked to infection.