NTN1 and colorectal cancer: In mammals, there are at least five genes encoding transmembrane receptors for Netrin-1: DCC (Deleted in Colorectal Cancer) and Neogenin receptors mediate the attractive response elicited by Netrin-1, whereas Unc5A–C family members mediate repulsion elicited by Netrin-1 either as homodimers or heterodimers with DCC [53,54].