NRP1 and neoplasm: Although these data support the role of NRP1 as a positive modulator of VEGF-A signalling, the fact that VEGF-A binding to NRP1 is dispensable for vascular permeability in vivo and that combining anti-NRP1 with anti-VEGF-A blocking antibodies has a synergistic effect on tumour angiogenesis and growth, suggests that NRP1 also promotes VEGF-A independent signalling [65].