This Funding Opportunity Announcement (FOA) invites grant applications aimed at elucidating neuroimmune and neuronal-glial pathophysiological mechanisms of HIV-associated neurological disorders (HAND) using ex vivo culturing platforms derived from human induced pluripotent stem cells (hiPSC) in the presence of addictive substances. Specific emphasis is on unbiased, reproducible analysis of genetics and epigenetics, neuroglial interactions, and neuroimmune cell activities from the single cell to neural circuit levels.: