On the contrary, over-expression of HDAC6, which is located in the cytoplasm and regulates deacetylation of α-tubulin in stable microtubules (Hubbert et al., 2002; Valenzuela-Fernandez et al., 2008), inhibits HIV-1 Env-mediated tubulin acetylation, thereby preventing HIV-1 Env-dependent cell fusion and infection (Valenzuela-Fernandez et al., 2005). The gene discussed is ERVW-1; the disease is infection.