THE ROOT OF THE CASE FOR JUNK DNA. “There are unambiguous examples of nonprotein-coding sequences of various types having been co-opted for organism-level functions in gene regulation, chromosome structure, and other roles, but at present evidence from the published literature suggests that these represent a small minority of the human genome.”
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351