Cover legend: This illustration shows one hemisphere of a Cxcr4-GFP;CXCL12-RFP double-transgenic, embryonic mouse brain. The Cxcr4-GFP reporter (green) strongly labels thalamocortical axons, which enter the cerebral cortex rich in CXCL12-RFP fusion protein (red). The chemokine CXCL12 ensures efficient intracortical progression of thalamocortical axons by interacting with its cognate receptor CXCR4. For more information, see the article by Abe et al. (pages 13053–13063).