Relative to glandular epithelial cells of deep infiltrating endometriotic lesions of uterosacral ligament, glandular epithelial cells of eutopic endometrium from women with or without endometriosis showed lower expression of Sema 3A (p = 0.028, p<0.001, respectively), NRP-1 (p<0.001, p<0.001, respectively) and Plexin A1 (p<0.001, p<0.001, respectively) (Fig 2A). Here, NRP1 is linked to endometriosis.