HUVECs were transfected with siRNA against PlexinD1 and plated on gelatin-coated coverslips. Confluent monolayers were treated with Sema3C-, Sema3Cp60- or control-conditioned medium for 30 min. Cells were fixed and stained with Alexa-Fluor 488-conjugated phalloidin to visualize F-actin. Arrows indicate Sema3C-induced cell membrane ruffling. Scale bar, 20 μm. Cell repellence was quantified as the number of cells with membrane ruffling normalized to the number of nuclei (n = 5; mean ± s.e.m., paired Student's t-test, **P = 0.001). 