CyDs. Next, we evaluated in vitro gene transfer activity of pDNA/CyDs/AF-liposomes in HepG2 cells, ASGP-R positive cells ( Figure 3 ). Here, we used pRL-CMV (CMV promoter) as pDNA and the charge ratio (AF-liposomes/pDNA) of 1.6 optimized by our previous study (data not shown). The gene transfer activity of pDNA/γ-CyD/AF-liposomes in HepG2 cells was significantly higher than that of pDNA/HP-α-, HP-β-, and HP-γ-CyDs/AF-liposomes ( Figure 3 ). Next, we measured the Renilla luciferase mRNA level after transfection of pDNA/CyDs/AF-liposomes in HepG2 cells by the RT-PCR method ( Figure 4 ). As predicted, γ-CyD significantly increased the luciferase expression, but HP-γ-CyD did not, suggesting that γ-CyD is involved in the enhancing effect on luciferase expression at or prior to a transcription process.