CD4 and melanoma: The cells were co-cultured with different human melanoma lines and following this, we measured secretion of TNFα and IFNγ (Fig. 4c-d); when normalized to the activity of F5 TCR only T-cells against different targets, both CD4+ and CD8+ T-cells transduced to express TIGIT-28/F5 secreted higher levels of cytokines than the control TCR-only transduced T cells (e.g. approximately 20–60% more IFNγ and TNFα secretion were observed in co-culture with different targets expressing high levels of CD155; p < 0.05).