Editing Small interfering RNA (section)

===Off-targeting ===
Off-targeting is another challenge to the use of siRNAs as a gene knockdown tool.<ref name=pmid1380154/> Here, genes with incomplete complementarity are inadvertently downregulated by the siRNA (in effect, the siRNA acts as a miRNA), leading to problems in data interpretation and potential toxicity. This, however, can be partly addressed by designing appropriate control experiments, and siRNA design algorithms are currently being developed to produce siRNAs free from off-targeting. Genome-wide expression analysis, e.g., by microarray technology, can then be used to verify this and further refine the algorithms. A 2006 paper from the laboratory of Dr. Khvorova implicates 6- or 7-basepair-long stretches from position 2 onward in the siRNA matching with 3'UTR regions in off-targeted genes.<ref>{{cite journal | vauthors = Birmingham A, Anderson EM, Reynolds A, Ilsley-Tyree D, Leake D, Fedorov Y, Baskerville S, Maksimova E, Robinson K, Karpilow J, Marshall WS, Khvorova A | display-authors = 6 | title = 3' UTR seed matches, but not overall identity, are associated with RNAi off-targets | journal = Nature Methods | volume = 3 | issue = 3 | pages = 199–204 | date = March 2006 | pmid = 16489337 | doi = 10.1038/nmeth854 | s2cid = 52809577 }}</ref> The tool of siRNA off-target predition is available at http://crdd.osdd.net/servers/aspsirna/asptar.php and published as ASPsiRNA resource.<ref name="pmid286969212">{{cite journal|vauthors=Monga I, Qureshi A, Thakur N, Gupta AK, Kumar M|year=2017|title=ASPsiRNA: A Resource of ASP-siRNAs Having Therapeutic Potential for Human Genetic Disorders and Algorithm for Prediction of Their Inhibitory Efficacy|url=http://crdd.osdd.net/servers/aspsirna/asptar.php|journal=[[G3: Genes, Genomes, Genetics ]]|volume=7|issue=9|pages=2931–2943|doi=10.1534/g3.117.044024|pmc=5592921|pmid=28696921}}</ref>