Focusing on the PlexinD1 receptor in breast cancer, PlexinD1 was shown to drive a significant increase in caspase-dependent cell death that was inhibited by recombinant SEMA3E, suggesting that SEMA3E’s potential oncogenic role may be in part through halting apoptosis induced by unliganded PlexinD1. Here, SEMA3E is linked to breast carcinoma.