Research suggests that co-expression of TIGIT and PD-L1 on CD8+ T cells recognizing tumor antigens enhances T cell proliferation and function across various cancer types with combined blockade, showcasing significant synergy, especially in melanoma patients.690,691 The CITYSCAPE trial involving 135 patients demonstrated the robust efficacy and tolerability of tiragolumab, a TIGIT inhibitor, in combination with atezolizumab (an anti-PD-L1 agent) for PD-L1-positive non-small cell lung cancer (NSCLC). This evidence concerns the gene CD8A and melanoma.