Cover legend: Artistic impression of a model depicting the development of sensory neuron subtypes signaling pain or thermosensation. The color code illustrates sensitivity to different chemical agonists such as capsaicin, the hot ingredient of chili pepper (red), the cooling compound menthol (green), or the irritant compounds cinnamaldehyde or mustard oil (yellow). Some cells respond to more than one stimulus and are coded in brown (capsaicin and menthol sensitivity) or orange (capsaicin and cinnamaldehyde sensitivity). The developmental lineages are captured by their emergence from the background, and circles and processes symbolize the soma and neurites of sensory neurons as well as their maturation and functional specification. For more information, see the article by Hjerling-Leffler et al. in this issue (pages 2435–2443).