Cover: Confocal section of a Drosophila third-instar larva brain hemisphere. Nuclei were segmented and assigned a colour according to the readout of a ratiometric hypoxia biosensor. Blue corresponds to highest oxygenation, while yellow corresponds to lowest oxygenation. The image is superimposed by a maximum-intensity projection of the brain's tracheal system (white). Note the topographical correlation between the extent of tracheal supply and the distinct hypoxic states of different brain regions. On page 296, Misra et al. discuss how different cellular hypoxic states correlate with tracheal supply in the brain. Image provided by Martin Baccino-Calace and licensed under a Creative Commons Attribution 4.0 International licence.