Although the discussion on the impact of Salmonella on PD-L1 expression is ongoing, research has shown that the combined administration of Salmonella and anti-PD-1 treatment effectively impedes tumor progression in colorectal cancer and melanoma animal models through a synergistic effect.702,703 In a mouse melanoma model, the co-delivery of Salmonella VNP20009 encapsulated in polydopamine with an anti-PD-1 peptide has provoked significant immune responses against tumors, resulting in their successful eradication. The gene discussed is CD274; the disease is colorectal cancer.