DNA damage and genomic instability. This is by creating reactive oxygen species, express proteins that interfere with DNA repair enzymes, and HCV causes activation of a mutator enzyme. Cirrhosis In addition to virus-related cirrhosis described above, other causes of cirrhosis can lead to HCC. Alcohol intake correlates with risk of HCC, and the risk is far greater in individuals with an alcohol-induced cirrhotic liver. There are a few disorders that are known to cause cirrhosis and lead to cancer, including hereditary hemochromatosis and primary biliary cirrhosis. Aflatoxin Aflatoxin exposure can lead to the development of HCC. The aflatoxins are a group of chemicals produced by the fungi Aspergillus flavus (the name comes from A. flavus toxin) and A. parasiticus. Food contamination by the fungi leads to ingestion of the chemicals, which are very toxic to the liver. Common foodstuffs contaminated with the toxins are cereals, peanuts, and other vegetables. The amount (dose) and how long (duration) that a person is in contact with aflatoxin is associated with HCC. Contamination of food is common in Africa, South-East Asia, and China. The mechanism by which aflatoxins cause cancer is through mutations and epigenetic alterations. Aflatoxins induce a spectrum of mutations, including in the p53 tumor suppressor gene, which is a mutation seen in many types of cancers. Mutation in p53, presumably in conjunction with other aflatoxin-induced mutations and epigenetic alterations, is likely a common cause of aflatoxin-induced carcinogenesis. Nonalcoholic steatohepatitis (NASH) and Nonalcoholic fatty liver (NAFL) NASH and NAFL is beginning to be called a risk factor for liver cancer, particularly HCC. In recent years, there has been a noted increase in liver transplantations for HCC that was attributable to NASH. More research is needed in this area and NASH/NAFL. Other risk factors in adults High grade dysplastic nodules are precancerous lesions of the liver. Within two years, there is a risk for cancer arising from these nodules of 30–40%. Obesity and metabolic syndrome have emerged as an important risk factor, as they can lead to steatohepatitis. Diabetes increases the risk for HCC. Smoking increases the risk for HCC compared to non-smokers and previous smokers. There is around 5-10% lifetime risk of cholangiocarcinoma in people with primary sclerosing cholangitis. Liver fluke infection increases the risk for cholangiocarcinoma, and this is the reason why Thailand has particularly high rates of this cancer. Choledochal cysts, Caroli's disease, and congenital hepatic fibrosis are associated with