PDCD4 and hepatocellular carcinoma: The high level of GFP expression in liver tissue indicates that the specific ligand–receptor interaction between the galactose part of the GPCS copolymer and ASGPRs may effectively transfer the tumor suppressor gene PDCD4 to hepatoma cells.408 In light of the pronounced upregulation of vascular endothelial growth factor receptor (VEGFR) in HCC and the positive correlation between up-regulation of AChE expression and apoptosis, Liu et al. coupled YC21 targeting EGFR to a PC vector composed of β-cyclodextrin and PEI600 to form the EGFR targeting gene vector YPC.