This is a very interesting article about the media. http://static-content.springer.com/image/art%3A10.1186%2F1471-2164-13-415/MediaObjects/12864_2012_4207_Fig3_HTML.jpg
http://static-content.springer.com/image/art%3A10.1186%2F1471-2164-13-415/MediaObjects/12864_2012_4207_Fig3_HTML.jpg