SAMHD1 and infection: At 4 and 6 dpi, we observed that the levels of BIK protein (Fig. 6D and E) and mRNA (Fig. 6F) in THP-1 Ctrl and SAMHD1 KI cells were higher than those in SAMHD1 KO and Lvx cells, regardless of HIV-1NL4-3 infection, suggesting that SAMHD1 increases BIK expression at both the protein and mRNA levels.