The luciferase expression in liver measured at 4–72 hrs is illustrated following hydrodynamic delivery of a 1 μg dose of mRNA to triplicate mice. Panel A illustrates the result of dosing ssmRNA, dsmRNA1, and dsmRNA2, and panel B illustrates the result of dosing PEG-peptide polyplexes. For significance, *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.