<qa>  What is the name of the study that is being performed in the parent trial?Evaluation of Subcutaneous Proleukin in a Randomized International Trial ESPRIT is a 4,000 patient, 6-year study investigating the clinical effect of interleukin-2 IL-2 in patients with HIV infection. Because of the size and duration of this study, substudies to the parent trial are being performed in order to improve the knowledge regarding the use of IL-2 in HIV-infected individuals and to enhance the overall scientific output of this international effort. This protocol will serve as the umbrella under which the ESPRIT substudies will be performed at the National Institutes of Health Clinical Center. 