For example, screening for Hp is indicated in case of a history of ulcer or active ulcer, complicated or not, without previously documented Hp, chronic dyspepsia with long-term treatment with proton pump inhibitors (PPI) (>6 months), iron deficiency anemia with no known cause or resistant to oral iron treatment, and vitamin B12 deficiency with no etiology found. The gene discussed is HP; the disease is ulcer disease.