The cytotoxin associated gene A (CagA) of Hp can reduce the immunotherapeutic effect of Hp infection on GC by inhibiting the proliferation and anti-cancer effects of p53 and miR-34a, as well as CD8+T cells, and increasing the level of PD-L1 in exosomes derived from GC cells (217). The gene discussed is S100A8; the disease is gastric cancer.