REGULATORY SEQUENCES. “Another class of regulatory RNAs, small interfering RNAs (siRNAs), are known to be related to TEs. Interestingly, this has been pointed out as a distinction between miRNAs and siRNAs, which are closely related in terms of structure, function, and biogenesis.” (TE = transposable elements; miRNA = microRNA).
http://www.genetics.org/content/176/2/1323