Our results show that ruxolitinib inhibition of Jak-STAT signaling impacts the susceptibility of uninfected cells to infection by HIV-1 at concentrations ≥ 0.01 μM (Fig 4B: representative dot plots, and Fig 4C: graphical representation) which are comparable to the ex vivo EC50 of 0.007 μM for ruxolitinib in CD4 T cells from viremic donors and well below the EC90 of 0.26 μM (Fig 2A). Here, CD4 is linked to infection.