We also examined the expression of Cxcr4, a chemokine receptor expressed in INP and neuroblasts in the DMS and in CRC, and its ligand Cxcl12, expressed by the meninges, and required for the migration of INP and CRC [19,26,33,34]; we also examined P73, a P53 homologue, marking CRC and important for hippocampal fissure and DG formation [35,36]. The gene discussed is CXCL12; the disease is colorectal carcinoma.