CD274 and liver cancer: In terms of mechanism, after XA5508 targets liver cancer cells, it releases cGAMP, activates the intracellular STING pathway, induces the production of immune cytokines, stimulates and activates CD8+ T cells, and simultaneously reverses the immunosuppressive TME characterized by M2-type macrophages, promoting the anti-tumor immune pathway to enhance the efficacy of anti-PD-L1 treatment.