Sterile-motif/histidine-aspartate domain-containing protein 1 (SAMHD1), a host restriction factor possessing dNTP triphosphohydrolase activity, has been reported to restrict HIV-1 infection in monocyte-derived macrophages (MDMs) by reducing the intracellular dNTP pool [129,130]. The gene discussed is SAMHD1; the disease is HIV-1 infection.