Actin-related proteins (ARPs) are present in organisms from fungi to humans. Whereas many of these have cytoskeletal functions (e.g. actin itself and the Arp2/3 complex), others function in more diverse processes, such as transcriptional regulation and chromatin remodelling. In Cell Science at a Glance on p. 2619, Holly Goodson and William Hawse present a phylogenetic analysis of the ARP family,taking advantage of the many sequences uncovered by the recent genome projects. On the basis of their analysis, the authors make some interesting predictions, suggesting, for example, that certain ARPs have ancient and underappreciated nuclear roles.