Silencing of Nrp-1 by lentiviral particles expressing shRNA. After culturing 72 h in selection medium, RNA was harvested for qPCR analysis. NS shRNA vs. Nrp-1 shRNA: #1, *P = 0.017 and #2, *P = 0.02; n = 3; mean ± s.e.m. Cell lysates were subjected to SDS-PAGE and probed with anti-Nrp-1. 