Hepatitis is chronic inflammation of the liver that can be caused by various viral infections. Two of the viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV), can cause chronic infection that may progressively damage the liver. One of the effects of chronic inflammation of the liver is widespread formation of scar tissue, a condition known as cirrhosis. In addition, chronic HCV infection is the most common cause of liver cancer (known as hepatocellular carcinoma [HCC]). Patients with cirrhosis are at greater risk for HCC than are those with hepatitis alone. Although researchers have suggested that people with chronic HCV infection are more likely to develop HCC if they have also been exposed to HBV, it is not known how much this exposure actually increases the risk for liver cancer.