In addition to the type of EPIYA-motifs, strains with amino acid polymorphism within the Western-specific EPIYA-B motif like EPIYT-B may influence CagA activity, reducing the ability to induce hummingbird phenomena and IL-8 expression conferring lower risk for gastric cancer and a higher risk for duodenal ulcer development [159]. The gene discussed is CXCL8; the disease is duodenal ulcer.