NUCLEAR HOME. “Strikingly, when one examines the steady state level of polyadenylated RNA, very little maps to intergenic regions. In fact, when one eliminates the ∼9,000 transcript species that are thought to be derived from conserved lncRNA, then most of the annotated noncoding polyadenylated RNAs are present at levels below one copy per cell and are found exclusively in the nucleus.” (LncRNAs = long non-coding RNAs).
http://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1004351