Activated T cell-derived exosomal PD-1 could either induce the internalization of PD-L1 on the surface of tumor cells via endocytosis or neutralize the tumor cell-derived exosomal PD-L1, both of which could exert a preventive role in the interaction of PD-L1 with PD-1 on the T cell surface, rescue the activity of tumor-specific CTLs, and restore tumor surveillance. The gene discussed is CD274; the disease is neoplasm.