Inclusion Criteria: Patients must meet all of the following inclusion criteria to be included in this study:

Age greater than or equal to 18 years. Documented laboratory diagnosis of HBV infection (HBsAg positive) at least 6 months prior to inclusion in this study. Treatment naive, HBeAg-positive and HBeAg-negative patients. At least one liver biopsy specimen obtained in 2004 and/or 2005 (post diagnosis) that is available for evaluation by an independent pathologist. Gilead may allow enrollment of subjects with biopsies available from 2003. An adequate section of a biopsy for the purposes of this study should have at least 1 cm of the needle core of tissue on the slide. HBV DNA greater than or less than 5 log10 copies/mL for HBeAg-positive and greater than or less than 4 log10 copies/mL for HBeAg negative patients. A minimum of two normal or minimally elevated hepatic transminases (ALT) values that are at least 3 months apart during 2004 and/or 2005. Gilead may allow enrollment of subjects with values available from 2003. Minimally elevated ALT is defined as between lower limit of normal (LLN) and 1.2 times upper limit of normal (ULN) for HBeAg-positive and between lower limit of normal (LLN) and 1.5 times upper limit of normal (ULN) for HBeAg-negative patients. Child-Turcotte-Pugh score less than 7 and no evidence of ascites, variceal bleeding, or hepatic encephalopathy or impaired clotting function within 12 months prior to the Enrollment Visit.

Exclusion Criteria:Patients who meet any of the following criteria are excluded from the study:

History or evidence of HIV, hepatitic C, or hepatitis D. Other causes for liver disease other than hepatitis B, including but not limited to: hemochromatosis, Alpha-1 antitrypsin deficiency, Wilson's disease, Drug-related liver disease, Autoimmune hepatitis, Alcoholic liver disease, Obesity-induced liver disease (nonalcoholic seatohepatitis, NASH). History of, or current alcohol or substance abuse judged by the investigator to potentially interfere with laboratory or biopsy results.