These proteins include unco-ordinated-5C (Unc-5C), another dependence receptor for netrin which can complex with DCC and which is absent from a variety of cancers [64–67]; Unc-5A: to assess the selectivity of serine proteases for unc5 family members; the small GTPase enzyme RhoA [68, 69]; Sonic hedgehog (Shh), a secreted protein involved in embryonic morphogenesis, cell location and polarisation [70, 71] and which modulates the expression of neogenin and netrin [72]. Here, RHOA is linked to cancer.