To ascertain whether endothelial NRP1 and NRP2 contribute in a nonredundant, synergistic manner during angiogenesis-dependent tumor development, we crossed NRP2flfl.Pdgfb-iCreERT2 (NRP2flfl.ECKO) mice with NRP1flfl.Pdgfb-iCreERT2 (NRP1flfl.ECKO) mice to generate NRP1flfl;NRP2flfl.Pdgfb-iCreERT2 (NRP1flflNRP2flfl.ECKO) animals and compared the effects of an acute endothelial-specific depletion of NRP1, NRP2, or NRP1;NRP2 during subcutaneous allograft tumor growth using CMT19T lung carcinoma cells. The gene discussed is NRP2; the disease is lung carcinoma.