In this context, it is worth mentioning that for neoantigens (peptide antigens encoded by tumor-specific mutated genes) expressing tumor cells, it could be shown that treatment with OMVs from E. coli (Won et al. 2023 [108]) increased activation and infiltration of CD8+ T cells, especially of those with high expressions of TCF-1 and PD-1. The gene discussed is CD8A; the disease is neoplasm.