SiRNA carrying an (E)-vinylphosphonate moiety at the 5΄ end of the guide strand augments gene silencing by enhanced binding to human Argonaute-2. Issue 8 (16th December 2016) - Elkayam, Elad; Parmar, Rubina; Brown, Christopher R.; Willoughby, Jennifer L.; Theile, Christopher S.; Manoharan, Muthiah; Joshua-Tor, Leemor