NRP1 and melanoma: Kruskal-Wallis test on the NRP1 scoring pattern in the patient samples revealed that NRP1 expression increased significantly from common nevi (mean 3.1) and dysplastic nevi (mean 4.2), to primary melanoma (mean 6.7) and metastatic melanoma (mean 70; P<0.0001, CN+DN vs. PM+MM; Fig. 2B).