This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is an amended protocol to continue study for 5 more years. The California NeuroAIDS Tissue Network (CNTN) is a consortium of three Californian Medical Centers (UC San Diego, UC Irvine, and Harbor-UCLA) which proposes to collect neurologic specimens from AIDS patients. Harbor-UCLA component of CNTN is designed to identify, recruit, enroll, and assess a cohort of approximately 85 patients with life expectancies of less than one year of whom about 6 will be autopsied each year. The majority of these patients have been enrolled during the past 8 years. Patients will be replaced as they die or are lost to follow up to mantain a cohort of 70 patients.