The Cornish Rex is a breed of domestic cat which has no hair except for down. Most breeds of cat have three different types of hair in their coats: the outer fur or "guard hairs", a middle layer called the "awn hair"; and the down hair or undercoat, which is very fine and about 1 cm long. Cornish Rexes only have the undercoat. Cornish Rex are prone to hair loss and many will develop a very thin coat or even go bald over large parts of their body. The curl in Cornish Rex fur is caused by a different mutation and gene than that of the Devon Rex. The breed originated in Cornwall, Great Britain. The coat of a Cornish Rex is extremely fine and sometimes curly. Their light coat means that they are best suited for indoor living in warm and dry conditions, as they are sensitive to low temperatures. Cornish Rexes like to stay near warm places such as computer monitors, light bulbs, laps and shoulders. The breed is sometimes referred to as the Greyhound of the cats, because of the sleek appearance and the galloping run characteristic of the breed. These cats tend to stay playful and kittenish throughout their long lives. Some Cornish Rexes like to play fetch, race other pets, or do acrobatic jumps. The Cornish Rex is an adventurous cat and is very intelligent. It can readily adapt to new situations and will explore wherever it can go. The Rex is extremely curious, seeks out the company of people and is friendly towards other companion animals. Cornish Rex cats come in a wide variety of coat colors and patterns, outlined in the breed standard: solids, including white, black, chocolate, orange and the dilutes blue, lilac and cream; all forms of tabby including classic, mackerel and ticked tabbies, bicolor "tuxedo" coat in many colors, tortoiseshell, "smoke" colors and the color-point pattern standard in the Siamese breed.