HCC are classified in metabolic pathways, and the most represented are the Aryl Hydrocarbon receptor signalling (AHR), involved in the activation of the cytosolic aryl hydrocarbon receptor by structurally diverse xenobiotic ligands (including dioxin, and polycyclic or halogenated aromatic hydrocarbons) and mediating their toxic and carcinogenic effects [81] and, protein Ubiquitination pathways, involved in cell-cycle regulation as well as cell death/apoptosis [82] through modification of target proteins. This evidence concerns the gene AHR and hepatocellular carcinoma.