To better establish the pro-invasive role of SEMA3F, we analysed the effects of the recombinant SEMA3F protein (RP-SEMA3F) on mild aggressive BC cells both in vitro and in vivo to test whether SEMA3F per se can promote invasion in these cells, which could make it a good candidate for a poor prognosis in patients with DCIS BC. The gene discussed is SEMA3F; the disease is ductal breast carcinoma in situ.