Competing endogenous RNAs act as molecular 'sponges.' What does this mean, and what do they compete with?

Enhancers can influence the transcription of genes far away on the same chromosome. How are the effects of enhancers restricted so that they do not exert inappropriate transcriptional activation of non-target genes?

What is one proposed role for lncRNAs?

What are the sources of dsRNA? Diagram the mechanisms by which dsRNAs are produced and processed into small RNAs.

How does dsRNA lead to posttranscriptonal gene silencing?

While circular RNAs were first described long ago, they have only recently been investigated for function. What are their known and suspected functions in the cell?