TNPO3 and infection: The role of TNPO3 in retroviral infection was initially discovered for HIV-1 [30]; however, more recent work has demonstrated that TNPO3 is also important for infection by HIV-2, simian lentiviruses, and, to a lesser extent, equine infectious anemia virus (EIAV) [31, 32, 37, 42] but not MLV or Feline immunodeficiency virus (FIV).