Nucleic Acids Research, 2010, Vol. 38, No. 15 5247 Figure 3. PR gene expression can be activated by agRNAs containing 20F-RNA. (A) Duplex sequences: passenger strands are listed on top in all cases; for agRNAs PR-11 and PR-22 this is the antisense strand. Modiﬁcation codes: dna, RNA, 20F-RNA; p = phosphate. (B) PR-11 analogs containing one strand heavily or fully modiﬁed with 20F-RNA. (C) PR-11 analogs containing a minimally 20F-RNA-modiﬁed guide strand. (D) PR-22 analogs containing one or both strands heavily or fully modiﬁed with 20F-RNA. All data are normalized to mismatch control MM4. RNA levels are the average (±SD) from at least two independent transfections. *P < 0.05, **P < 0.01, ***P < 0.005. Protein levels were also conﬁrmed by at least two independent transfections, from which a typical western blot is shown.