Oligonucleotides are short single-stranded sections of DNA orRNA that contain 20-deoxyribo-nucleosides or ribo-nucleosides,respectively, which are linked by 30–50phosphodiester linkages(Fig.1a). Antisense oligonucleotides are those that are complemen-tary to a section of naturally occurring RNA, such as an mRNA or aviral RNA, to form Watson–Crick base pairs and to thus inhibit abiological f…