PROJECT SUMMARY/ ABSTRACT (for Alina Pang (Ndhlovu): R01 AG063846-01A1 Supplement Application) In this application, we seek a diversity research supplement to parent award “HARNESSING SINGLE CELL EPIGENOME-WIDE PROFILING OF MYELOID CELLS TO COMPARE AND CONTRAST ALZHEIMER'S FROM HIV-ASSOCIATED COGNITIVE DYSFUNCTION” (AG063846-01A1). The parent award seeks to define the epigenomic landscape of myeloid populations in order to differentiate HIV Associated Neurocogntivie Disease (HAND) from Mild Cognitive Impairment state of Alzheimer’s Disease (MCI-AD) in individuals living with HIV on suppressive antiretroviral therapy (ART). This diversity supplement will expand the scope of research in Specific Aim 1 to include epigenetic signatures of cell free DNA (cfDNA) to further aid in elucidating the pathogenesis of neurocognitive impairment observed in people living with HIV (PLWH) and provide postdoctoral training in epigenetics and immunology in the pathogenesis of HAND. The goal of the diversity supplement is for Dr. Pang to gain experience and preliminary data on epigenetic signatures in the periphery specific to neurocognitive impairment to submit a K01 application in 2023.