A functional siRNA library screen identifies 6 putative GEF downstream of vGPCR. A. Schematic of GEF siRNA permeability screen. B. The fluorescence intensity was determined for each targeting sequence (2 sequences/target) and expressed as means of the ratio to control siRNA-transfected cells (4 non-silencing control sequences). Shared hits between vGPCR and IL-8 screens are highlighted in red. C. A two-step screen was performed; the first examined vGPCR-driven permeability. Hits from that screen were then tested for involvement in IL-8-driven permeability. The six GEFs that significantly decreased permeability when silenced are indicated.