Breast cancer patients with advanced diseased nodes N3 displayed significantly higher plasma NRP-1 compared to patients with no nodal metastasis N0 (p = 0.003), less advanced nodal metastasis N1 (p = 0.023) and N2 (p = 0.018) and to healthy controls (p = 0.002) (Fig. 1a). Here, NRP1 is linked to breast cancer.