RNA interference (RNAi) is a biological process in which small RNA molecules inhibit gene expression. This occurs when double-stranded RNA is introduced into a cell, leading to the degradation of specific messenger RNA (mRNA) molecules. As a result, the production of proteins encoded by those mRNAs is reduced or silenced. RNAi plays a crucial role in regulating various cellular processes, including development and defense against viruses. Researchers are exploring its potential applications in gene therapy and drug development, as it offers a way to target and silence harmful genes associated with diseases.