ABSTRACT Kaposi Sarcoma (KS) in people living with HIV today is not the same disease as AIDS-KS in 1990s San Francisco. In the UNC Lineberger Comprehensive Cancer Center Capture area, KS cases disproportionally manifest in African Americans. In the US, one-third of HIV-KS now manifests in people with average CD4 counts and no detectable HIV. We need to understand what has changed in the clinical and molecular phenotypes of KS as they present in 2024. This supplement application responds to “Administrative Supplements for P30 Cancer Centers Support Grants (CCSG) to Stimulate Research in HIV/AIDS Cancer Research Projects at NCI-Designated Cancer Centers,” specifically the NOFO to “utilize biospecimens from the AIDS and Cancer Specimen Resource (ACSR)* inventory (or another certified biorepository); data from existing cohorts; and/or biospecimens and clinical data from the cancer center itself, including international partnerships of the center.” Firstly, we will use specimens from AMC-066 and AMC-067 available through the ACSR to understand the importance of KSHV viral load measurements as predictors of progressive disease and AMC-098 Nivolumab samples. Secondly, we will use the identical specimens to generate a comprehensive BCR survey of PLWH and KS. AMC-066 and AMC-067 were the most extensive prospective randomized trials in KS ever conducted. Each sample is connected to outcomes and clinical correlates. Thus, the molecular data will not stand alone but will be connected to de-identified clinical data to generate a rich, high-dimensional data set for the field and the future.