PDCD1 and neoplasm: Likewise, the use of EVs derived from the outer membrane of Gram-negative bacteria (GNB) genetically modified to express PD-1 are effective in modifying the TME by increasing infiltration by DCs, NK cells and Tc cells, and stimulating the secretion of IFN-γ, TNF-α and IL-6, thus generating greater effectiveness than anti-PD-L1 antibody treatment at inducing an effective anti-tumor immune response [166].