The factors and receptors analyzed were IL6, CSF2, CCL5, VEGFA, VEGFC, GP130, GMRA, GMRB, CCR5, VEGFR2, NRP1, VEGFR3, and NRP2, because we found their protein expression to be critical to basal breast cancer metastasis in previous studies4, 12. Here, NRP1 is linked to breast cancer.