This study is about using and testing leftover samples, like blood, from past and future medical trials. These samples are called Human Biological Materials (HBM). Sometimes, scientists want to study these samples again to learn more about diseases like HIV. To do this, they need permission from the person who gave the sample. This permission is called informed consent, which means you agree to let them use your sample for new studies. If you agree, you might also be asked to give a small blood sample for future genetic testing. Don't worry, not agreeing won't affect your participation in other medical trials. The study aims to use these samples to help research while keeping your identity safe. If you have ever been in an Adult AIDS Clinical Trials Group (AACTG) or are currently in one, you can participate in this study.

• The study does not affect participation in other trials.
• Consent can be given any time, even after a trial is over.
• Your identity will be protected during the study.