Similarly, Nie et al. 74 designed an ε-polylysine cationic co-polymer to efficiently take up negatively charged si-HIF1a on the surface and encapsulate gemcitabine at the hydrophilic core, then further coating with PEGylated lipid bilayer to reverse the surface charge, which demonstrated excellent ability to inhibit tumor metastasis in orthotopic tumor models. This evidence concerns the gene HIF1A and neoplasm.