The ability of endogenous SAMHD1 to bind to in vitro assembled HIV-1 CA-NC complexes were measured in extracts from cells that do not express MxB (THP-1-MxB-KO) as described in Methods. As a control, similar experiments were performed using extracts from control THP-1 cells that do express MxB. Input and Pellets fractions were analyzed by Western blot using anti-MxB, anti-SAMHD1, and anti-p24 antibodies. Similar results were obtained in three independent experiments and a representative experiment is shown. * denotes P value < 0.05, ** denotes P value < 0.005, *** denotes P value < 0.0001 as determined by One-way ANOVA Tukey’s multiple comparisons test.