PDCD1 and neoplasm: Further studies also showed that combining GDVLNs with the monoclonal antibody programmed cell death protein-1 (PD-1) significantly increased the number of infiltrating T cells in colon and breast cancer TAM, showing a shift from a “cold tumor” to a “hot tumor,” and enhanced long-term antigen-specific anti-tumor memory, inducing durable systemic anti-tumor immunity.