Furthermore, pericyte coverage is reduced in brain microvessels both in biopsies from patients with HIV encephalitis and in transgenic (Tg26) mice expressing Tat and other viral gene products from an HIV-1 proviral genome lacking the gag and pol genes [34], suggesting that Tat-induced pericyte dysfunction and/or loss may contribute to the progression of HAND. The gene discussed is TAT; the disease is HIV-associated neurocognitive disorder.