Transfer of luciferase-coding RNActive in vivo in human skin. GMP quality RNActive-coding luciferase was produced and dissolved at 0.8 μg/μl in Ringer lactate solution. As shown in (a), the injection of 100 μl of this GMP quality solution in mouse ears resulted in the production of more luciferase in comparison to laboratory-grade RNActive (‘Lab’). The same solution injected intradermally in human resulted also in the in vivo production of luciferase as detected in a 3-mm diameter punch biopsy made on the middle of the injection site (forming a bubble of ca. 2 cm in diameter) 16 h after injection (b). A punch biopsy made outside the injected zone did not contain detectable luciferase activity. GMP, good manufacturing practice.