A key restriction factor for HIV-1 infection that we characterized is the cytoplasmic enzyme HDAC6 (histone deacetylase 6) [70,71,72,126,127,142,205], and more recently the transactive response of the DNA-binding protein (TARDBP or TDP-43) together with HDAC6 (i.e., the TDP-43/HDAC6 axis) [127]. The gene discussed is TARDBP; the disease is HIV-1 infection.