http://news.bbc.co.uk/olmedia/1720000/images/_1722218_wiredupclose300.jpg

Could this be the key to unlocking the body's sleep cycle and thus be the key to a suspended sleep cycle that might allow us to sleep our way to the stars?

http://news.bbc.co.uk/hi/english/health/newsid_1722000/1722218.stm

Good research. It is like six blind people describing an elephant. The eyes are not the only sensors - think about the blind people. The skin may be another that uses the amount of UV present as a signal. TGF-alpha is the result and not the cause of sleep cycle.

May be they will stumble onto something....

well it's already known that the Skin is sensative to sunlight, Well the UV part of its spectrum. (without this concerning race I hope) A white persons skin will tan if subjected to strong (UV)sunlight, due to the content of Melatonin within the Skin.

This means the body at a cellular level is reactive to the sun (This doesn't meant that people of an Ethnic group other than that I have mentioned don't suffer from sunburn, it just means there bodies have a naturally higher amount of Melatonin)

Melatonin is produced from a chemical called melalin, that is controlled by the Pineal body within the brain. It for many years has been questioned as to being a point for "Light sensativity", as Melalin is produced in higher quantities at NIGHT. (This is why all those computer geeks that stay up all night fighting on computer games, go a little pastey in colour, because they have inhibited their Melalin production)

It's noted that Melalin acts as a natural UV block, although not to a major extent and is used in the reconstitution of Pupils (The black centre of the eyes) during sleep. (since UV damages the eye over time, thats why your eyes sting if you try staying up for too long)

In later life the Pineal body is suppose to suffer from "Crystalisation", This can cause the Melalin production to drop to a level that is near none existance, and causes Anemia (Anaemia).

(There is a high possibility that from this information, it can be Drawn that the Plastic Surgery that Michael Jackson has had over the years, could have caused his discolouration, from his Melalin levels being tampered with due to the new skin tissue.)

Added:
Just to add to this from a Neo-Darwinism Perspective. There have been theories that mankind originated from what is now known as Africa, and that Mankind was coloured in Origin. The explaination of age causing Crystalisation of the Pineal body, might actually be enough to deduce that if Hunter-Gatherer humanoids leanrt agrarian traits of growing crops, and their age expectancy rose, if a female became pregnant later in life, it would be while their was an amount of Crystalisation within the Pineal Body.

This means that Generation after generation could pass, getting preganent at a later life point, and cause a Genetic change that would eventually cause the creation of pailer skin.