Although it is commonly associated with chronic infection caused by hepatitis B virus (HBV), hepatitis C virus (HCV), alcoholic cirrhosis or aflatoxins [81], an increasing percentage of diagnosed cases of HCC has been suggested to be related to disruption of the circadian clock, obesity and non-alcoholic fatty liver disease (NAFLD) [82,83]. The gene discussed is CLOCK; the disease is hepatocellular carcinoma.