The purpose of this study is to offer subjects from centers in Taiwan who successfully complete 168 weeks of treatment in study GS US 174-0108 access to treatment with tenofovir DF for up to three additional years (144 weeks). Subjects will be followed per local standard of care. Serious adverse events (SAEs), drug accountability and patient disposition will be recorded.

Inclusion Criteria:

Subjects must meet all of the following inclusion criteria to be eligible for participation in this study.

• Complete all end of study visit procedures for the GS US 174-0108 study.
• Willing and able to provide written informed consent.
• A negative pregnancy test is required for female subjects at the end of study visit (i.e., screening visit for study GS-US-174-0141) for GS US 174-0108 (unless surgically sterile or greater than two years post-menopausal)
• All sexually active female subjects who are not post menopausal, or surgically sterile and are of childbearing potential must agree to use a highly effective method of contraception during heterosexual intercourse throughout the study.
• Male subjects who are sexually active are required to use barrier contraception (condom with spermicide) during heterosexual intercourse through to study completion.

Exclusion Criteria:

• Not Applicable