However, given that the RT Q151N mutation might be expected to reduce nascent viral cDNA production, we analysed the effects of SAMHD1 tetramerisation on restriction of WT HIV-1 and the RT Q151N by qPCR quantification of viral cDNA after infection of both cycling and differentiated U937 cells expressing either WT SAMHD1, the Tetstable T592C mutant or the Tetunstable T592D mutant. This evidence concerns the gene SAMHD1 and infection.