A) Vero, HSAEC, or MEF cells were mock-infected or infected with MP12 or MP12-ΔNSs at MOI 3.0 for one hour. Cell lysates were collected at 8, 16, and 24 hpi and analyzed by western blot. Membranes were probed for p-STAT3 (Y705), RVFV nucleoprotein (NP), and β-actin as a loading control. B) Vero cells were transfected with 2.5 μg of NSs-Flag plasmid or pcDNA as a control. At 24 hours post transfection, cell lysates were collected and analyzed by western blot for p-STAT3 (Y705), RVFV NSs (Flag-tag), and β-actin as a loading control. Blots from two independent experiments (5 biological replicates) were quantified for p-STAT3 (Y705) and a representative blot is shown. ** p ≤ 0.005