Cover legend: Confocal immunofluorescence image shows the overlapping expression of Lmx1b (red) and 5-HT (green) in the rostral part of the hindbrain of wild-type mice at embryonic day 11.0. Yellow color indicates double staining of Lmx1b and 5-HT. For more information, see the article by Zhao et al., in this issue (pages 12781–12788).