Since DCs are rare in human peripheral blood [7], we focused on (a) the enumeration of the two major DC subsets (CD11c+ mDCs and CD123+ pDCs) and (b) the estimation of the correlation between these DC phenotypes, H. pylori-induced inflammation and H. pylori density scores, according to the updated Sydney system of gastritis classification. The gene discussed is IL3RA; the disease is gastritis.