Cover Photograph: Non-coding RNAs take centre stage molecular biology: there is still uncertainty as to whether the majority of these molecules are functional. However, findings implicating different classes of non-coding RNAs in epigenetic mechanisms are emerging with increasing speed. The cover image depicts the secondary structure of the long non-coding RNA HOTAIR (using the RNA Fold software), which is implicated in gene regulation by epigenetic mechanisms. This ncRNA is ∼2 Kb long and was recently revealed to be associated with chromatin remodeling and, more particularly, cancer progression in breast tumors. In this issue, Fabrício Costa presents the already huge, but rapidly expanding, diversity of these gene regulatory factors in the review essay “Non-coding RNAs: Meet thy masters”.