The latter suggested that the antiviral activity of the DDC biosynthetic pathway on HCV is not due to the autocrine/paracrine activation of the dopamine receptor D2, which has a well-characterized function in the liver, in inhibiting proliferation and migration and promoting apoptosis of HCC cells [63,64] and in regulating the detoxification function of hepatocytes [65]. This evidence concerns the gene DRD2 and hepatocellular carcinoma.