One such paradigm is the silencing of proprotein convertase subtilisin/kexin type 9 (PCSK9) gene encoding for proprotein convertase subtilisin/kexin type 9 protein, which reduces the levels of LDL receptors (LDLR) on the surface of a variety of cells, such as mice hepatic cells in vivo and human hepatoma cells (HepG2 and HuH7) or human embryonic kidney cells (HEK-293 cells) in vitro, leading to increased LDL-C in circulation [100]. Here, PCSK9 is linked to hepatocellular carcinoma.