In this study, we first created expression plasmids encoding human and mouse LEDGF/p75 (hLEDGF/p75 or mLEDGF/p75, respectively) to compare their ability to support HIV-1 infection in mouse embryonic fibroblast (MEF) cells, and found that the expression of hLEDGF/p75 rendered MEF cells more sensitive to HIV-1 infection than that of mLEDGF/p75. Here, PSIP1 is linked to HIV-1 infection.