This image shows myelin (cyan) and axons (magenta) of dorsal root ganglia neurons taken from embryonic day 13.5 mice and cultured for 12 days to allow axonal growth and myelination. Schwann cell nuclei are labeled with Dapi (blue). For more information, see the article by Sidoli et al. (pages 4536–4548). Cover image: Mariapaola Sidoli