We then infected monocytes with TB40E SV40-GFP WT HCMV, and at 3 h.p.i, either left them untreated, treated them with two different concentrations of rotenone, or treated the cells with IL-4 and GM-CSF; IL-4/GM-CSF which differentiates the cells and acts as a positive control (since differentiated monocytes support a lytic infection). Here, IL4 is linked to infection.