In HAND models, cannabinoids protect dopaminergic neurons against damage from the HIV envelope glycoprotein gp120 (Hu et al., 2013), reduce Tat-induced release of nitric oxide (Esposito et al., 2002), and diminish Tat-induced increases in neuronal [Ca2+]i (Xu et al., 2017). Here, ERVW-1 is linked to HIV-associated neurocognitive disorder.