KDR and hepatocellular carcinoma: Zhang et al. developed lactose acid-modified chitosan NPs to deliver the CRISPR/Cas9 system for the knockout of the vascular endothelial growth factor 2 (VEGFR2) gene in liver tumor cells, and they demonstrated that the average intratumoral fluorescence intensity of these NPs at different time points was stronger than that of free labeled dyes, which indicated that this nanosystem carried out effective drug delivery and enhanced tumor accumulation for great curative effects of hepatocellular carcinoma (HCC) [85].