Similarly, gliomas exhibit elevated GDNF levels, which enhance migration via the MAPK and JNK pathways and confer chemoresistance, while Growth Arrest Specific 1, a protein that is structurally homologous with the GFRα receptors, blocks this process by inhibiting RET signaling (Song and Moon, 2006; Domínguez-Monzón et al., 2009; Ng et al., 2009). This evidence concerns the gene GDNF and central nervous system cancer.