[5] It should not be confused for the protein CD200R1 which shares the alias OX2R but is a distinct, unrelated gene located on the human chromosome 3.

[6] The structure of the receptor has been solved to 2.5 Å resolution as a fusion protein bound to suvorexant using lipid-mediated crystallization.

[8] This receptor is activated by Hipocretin, which is a wake-promoting hypothalamic neuropeptide that acts as a critical regulator of sleep in animals as Zebrafish or Mammals.

This protein has mutations in Astyanax mexicanus that reduces the sleep needs of the cavefish.

[9] This article incorporates text from the United States National Library of Medicine, which is in the public domain.