Ready-to-use ELISA kits are available for the detection of histamine receptor H 2, an alias of the protein, histamine receptor H2. The official gene symbol is HRH2. The protein, with a mass of 40.1 kDa and length of 359 residues, is reported to be membrane-associated. It is a member of the G-protein coupled receptor 1 family and may be known by other names, including: H2R, gastric receptor I, gastric receptor 1, and histamine H2 receptor.