In vivolung transfection of K18-lacZ with lacZ siRNA. LacZ siRNA (Z7) or control siRNA was complexed to GL67 (40 μg/mouse), placed as a bolus (100 μl) onto the nostrils of anaesthetised mice and "sniffed" into the lung. Forty-eight hours after transfection the lungs were harvested and βgal mRNA (A) and protein expression (B) were quantified. Each diamond represents an individual animal. The mean per group is indicated as a horizontal bar. * indicates p < 0.05 when compared to control group.