S100A8 and neoplasm: The peptidoglycan of the former can bind to the TLR2 receptor on the surface of tumor cells and induce inflammatory responses, and the latter activates nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling in host cells with the help of synergistic effects of the cytotoxin-associated gene A (CagA), vacuolating cytotoxin A (VacA), and peptidoglycan, which are involved in the development of gastric cancer [63,64].