To examine the roles of YTHDF1–3 proteins in post-entry HIV-1 infection, we either overexpressed or knocked down the individual YTHDF proteins in human cell lines, and examined the effect on HIV-1 infection using a single-cycle, luciferase reporter HIV-1 pseudotyped with vesicular stomatitis virus G protein (VSV-G) to overcome the requirement of HIV-1 receptors during viral entry (Wang et al., 2007). Here, PROS1 is linked to HIV-1 infection.