from Alka Saxena and Piero Carninci writing in Epigenetics: A Reference Manual:
In the past decade, we have become acquainted with an entire new world of fine regulatory control within cells governed by non-coding RNAs. Although we have not completely explored this world, we know from a few well studied examples that not only gene dosage but protein function also, is fine tuned by non-coding RNAs. It appears that proper cell function is largely dependent on non-coding RNAs, many of which were invisible to us until the advent of high throughput sequencing and tiling array technology. The realization, that transcripts with no open reading frames are biologically active molecules with multiple functions including regulation of the expression of coding RNA, shifts the power from proteins to non-coding RNAs as key modulators of cellular function. In this review, we discuss the various classes of non coding RNAs and the mechanisms employed by them to achieve this status, with a particular focus on their ability to induce epigenetic modifications.
Further reading: Epigenetics: A Reference Manual