It is believed that TNPO3 is involved in nuclear import of the HIV-1 PIC on the basis of the following evidence [29]: (1) reduction in the number of 2-LTR circles during HIV-1 infection of TNPO3-depleted cells when compared to infection of wild-type cells and (2) observation of decreased nuclear translocation of the PIC in TNPO3-depleted cells by using an HIV-1 virus containing an IN-GFP fusion protein. This evidence concerns the gene TNPO3 and infection.