The Siberian is a centuries-old landrace (natural variety) of domestic cat in Russia and recently developed as a formal breed with standards promulgated the world over since the late 1980s.
Siberians vary from medium to large in size. The formal name of the breed is Siberian Forest Cat, but usually it’s simply called the Siberian or Siberian cat. Another formal breed name is the Moscow Semi-Longhair. The cat is an ancient breed that is now believed to be ancestral to all modern long-haired cats. The cat has similarities with the Norwegian forest cat, to which it is likely closely related. It is a natural breed from Siberia and the national cat of Russia. While it began as a landrace, it is selectively bred and pedigreed today in at least seven major cat fancier and breeder organizations. The colorpoint variant of the breed is called the Neva Masquerade by some registries, including Fédération Internationale Féline (FIFé).
The Siberian (along with the Russian Blue, Balinese, Cornish Rex, Sphynx and several others) produces less Fel d 1 than other cat breeds and, while it is certainly not completely so, is often called hypoallergenic. A research study of Siberian cats native to the area of Russia from which the breed stock originated confirmed the subjects produced less Fel d 1 (the strongest among the eight known Fel d allergens produced in cat saliva and skin and therefore found in cat dander) than non-Siberian cats.