This work presented UCNP-Ce6-R837, an immune-stimulating UCNP-based PDT strategy, in combination with the cytotoxic T lymphocyte-associated protein 4 (CTLA-4) checkpoint blockade, to destroy primary tumors potently under light exposure, inhibit distant tumors that can hardly be reached by light, and prevent tumor reoccurrence via the immune memory effect [86]. The gene discussed is CTLA4; the disease is neoplasm.