These results are in line with work from other groups, showing that Vpx of the SIVSM/HIV-2 lineage acts on cytoplasmic SAMHD1 protein, a HIV-1 restriction factor expressed in cells of the myeloid lineage that inhibits an early step of the viral life cycle, and demonstrating that SIV-Vpx induces proteasomal degradation of SAMHD1, ultimately enhancing HIV-1 infection in myeloid-lineage cells [22,23]. This evidence concerns the gene SAMHD1 and HIV-1 infection.