It represents an established target for the treatment of gastroesophageal reflux disease (GERD) and peptic ulcer, with H2R antagonists, like cimetidine, ranitidine and famotidine (2–4, Fig. 1) being some of the first blockbuster drugs on the market in the 1970s5. This evidence concerns the gene HRH2 and gastroesophageal reflux disease.