Revisiting IncRNAs: How Do You Know Yours Is Not an eRNA?

Diverse classes of noncoding RNAs have been recently established, but the defining criteria for each class are not always obvious. New research from Paralkar et al. (2016) in this issue of Molecular Cell challenges the distinction between long noncoding RNAs and enhancer-derived RNAs, and provides an experimental approach to define their mechanism of action.