SAMHD1Q548A (dNTPase-positive) showed a similar infection ratio to SAMHD1mock despite having the ability to deplete the intracellular dNTP pool (Figure 1a), suggesting that SAMDH1 acts as an HIV-1 restriction factor via its RNase activity rather than via its dNTPase activity as previously described [10–13]. This evidence concerns the gene SAMHD1 and infection.