Figure 2From: Tumor-directed gene therapy in mice using a composite nonviral gene delivery system consisting of the piggyBac transposon and polyethylenimine Transgene expression in vivo. Fluorescence micrographs of pPB/TK-transfected tumor cryosections show that mRFP1 expression was observed three weeks after transfection. Empty vector was used as control. (Magnification, ×200).Back to article page