Cover legend: Confocal micrograph of cross section through a the forebrain of a stage 37/38 Xenopus laevis embryo. Immunostaining for nuclear lamins II/III (magenta) labeled the nuclear envelope. Subcellular localization of heterogeneous nuclear ribonucleoprotein K (hnRNP K) was visualized by its expression as a fusion with Enhanced Green Fluorescent Protein (green). During neuronal development, hnRNP K is highly enriched in the nuclear compartment, while a small subset shuttles to the cytoplasm, where its post-transcriptional regulation of mRNA targets essential for axon outgrowth is mediated by c-Jun N-terminal kinase. For more information, see Hutchins and Szaro (14666–14680).