CXCL8 and gastric cancer: Virulence factors in H. pylori (specially the presence of the CagA oncoprotein and of the toxic form of the vacuolating cytotoxin VacA) and host polymorphisms in genes that alter cytokine expression (IL-1β, TNF-α, IL-10, IL-8, and COX-2) have been linked to an increased risk for gastric cancer development [16].