Because NK activities can be modulated by the different types of H. pylori antigens [36] and it tends to disappear when advanced atrophy and intestinal metaplasia extend [35], a prospective investigation of NKA-IFNγ in patients with benign gastric disease as well as patients with other cancers should be carried out to validate the diagnostic performance of NKA-IFNγ assay. The gene discussed is IFNG; the disease is cancer.