This family consists of several outer membrane proteins found only in Helicobacter pylori, which is the causative agent of gastritis and peptic ulceration in humans. The outer membrane proteome profile of Helicobacter pylori differs from that of other Gram-negative bacteria. Outer membrane proteins of Helicobacter pylori are characterized mainly as adhesins and porins, while extensive C-terminal sequence similarity between these proteins has been used to define this large paralogous family. Hof (H. pylori outer membrane protein family) is another Omps subfamily composed of 8 members, two of which (HofC/Hp0486 and HofD/Hp0487) are exported via an N-terminal signal peptide.