According to janie6789 (writer of Kyuhyun, it's been hard on you):

"This is a cancer lab in McGill University.

Medicom company is sponsoring them, and for each hit they get on Youtube, they are making donations to the lab so they can do more research.

PLEASE SUPPORT, REBLOG, AND LET'S HELP MAKE THIS VIDEO VIRAL!!!!!" (janie6789, 2011)

http://www.youtube.com/watch?feature=player_embedded&v=Hg1yw8D3glE

P.S. I apologize if I just gave you the link. I do not know how to post the video itself. I have yet to find out how to do it!