 Small interfering RNA

A short RNA that guides sequence-specific silencing through an Argonaute protein; different pathways use different lengths and targets.

Small interfering RNA (siRNA) is a class of double-stranded RNA molecules, typically about 20 to 25 base pairs in length, that play a crucial role in the process of RNA interference (RNAi). siRNA is involved in the regulation of gene expression and the defense against viral infections and transposable elements in cells.