Primary liver cancer is the third most deadly and fifth most common cancer worldwide (~500,000 deaths annually), with a sharp increase of incidence in the United States in recent years. Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) are the major types of primary liver cancer. Risk factors include gender, hepatitis B virus (HBV), hepatitis C virus (HCV), cirrhosis, metabolism diseases, diabetes, obesity, toxins, excess alcohol consumption and smoking. Liver cancer arises most frequently in inflammatory livers with extensive oxidative stress due to viral hepatitis which causes over 80% of HCC cases worldwide. Currently, survival remains dismal for most HCC and CC patients, largely due to the tumor aggressiveness at the time of diagnosis and the lack of effective therapy.