SAMHD1 and HIV-1 infection: The experiments in in vitro cell cultures demonstrate that SAMHD1 restricts HIV-1 infection in non-dividing cells such as macrophages (plus phorbol 12-myristate 13-acetate-stimulated macrophage-like THP-1 cell line), DCs, and resting CD4+ T cells by degrading dNTPs (18, 19).