Olfactory receptor (OR) genes form the largest known multigene family in the human genome []. Each olfactory receptor does not seem to detect a single odour. Instead, different odorants are recognised by different combinations of olfactory receptors []. Olfactory receptors can be assigned to subfamilies on the basis of sequence relationships. Members of the same subfamily have related sequences and are likely to recognise structurally related odorants. In humans, 339 intact OR genes and 297 OR pseudogenes have been identified [].This entry represents OR10G4 (olfactory receptor, family 10, subfamily G, member 4) and OR10G9 from mammals.
