In a panel of 68 primary breast cancer biopsies, it appeared to be the overexpression of SEMA3E but not the PlexinD1 receptor that drove BC progression, since SEMA3E mRNA levels were significantly higher in patients with distant breast cancer metastasis at diagnosis compared to those patients whose tumours were localised to the breast, whereas PlexinD1 levels were similar in both. This evidence concerns the gene SEMA3E and breast cancer.