At 24 hours, Luciferase activity was not detected in any animal groups. We explain this finding by the time needed for the reporter gene to express. However, at 48 hours, luc activity (detected as luminescence by the CCCD camera) was seen over the lung areas in 2CLP animals given SV/luc (Figure 2a) . Low levels of luc activity were detected in the tracheostomy region, confirming a degree of vector affinity for airway epithelium (Figure 2b ). No luc activity was detected in rats given PBS. No significant in vivo luc activity was detected in the heart, liver, spleen or kidneys of the animals given SV/luc.