SAMHD1 and infection: Finally, we measured plaque-forming units (PFUs) for the different treatment groups, and found that Vpx+ VLP treatment led to a 1.8- to 4–6-fold increase in the amount of infectious viral particles produced as compared to Vpx− VLP treatment (Fig. 1C), To further confirm that the increases observed in infection frequency and PFUs were solely due to Vpx-mediated SAMHD1 degradation, a composite of all the experiments is presented in Fig. S2, showing that the no VLP treatment group was comparable to Vpx− VLP treatment group in all parameters.