The PCR and western blot analyses exhibited similar results to the immunostaining. The reverse transcription-PCR (RT-PCR) representative images (Figure 4d ) illustrate high exon skipping efficiency in all tissues analyzed. This is better shown by quantitative real-time PCR (qRT-PCR) results for the quadriceps, diaphragm and heart (Figure 4c) . The delta 23 transcript is normalized against "total dystrophin" for each muscle group (n = 3). Quantification of this data revealed similar levels of ∆23 skipping in the quadriceps of all 5-aa Pip6-PMO-treated mice. The data trends suggest that Pip6f-and Pip5e-PMO show the highest exon skipping in the diaphragm, and Pip6f-PMO the highest in heart (for splicing mean values, see Supplementary Figure S2a ). Western blots (Figure 4e) were performed on the tissues of each mouse and were quantified against a 50 and 10% C57BL10 control. These results were averaged and are presented in Supplementary Figure S2b. Pip6a-, Pip6b-, Pip6e-, and Pip6f-PMO conjugates exhibited the highest dystrophin protein restoration in the TA and quadriceps muscles. The levels of dystrophin restoration in the diaphragm were uniform across all of these treatments, whereas in the case of the heart, Pip6b-and Pip6f-PMO conjugates showed the highest dystrophin restoration.