HUVECs were transfected with siRNA against PlexinD1 or control NS (non-silence) siRNA. qPCR analyses and Western blotting were performed after 48 h (n = 3; paired Student's t-test, NS siRNA vs. PlexinD1 siRNA, ***P = 0.0004). Cell lysates were subjected to SDS-PAGE and probed with anti-PlexinD1. 