WormBook now contains over 80 published contributions. Chapters recently added to WormBook include: Somatic sex determination, RTKRas/MAP kinase signaling, Mechanism and regulation of translation in C. elegans, Homologs of the Hh signalling network in C. elegans, Cell division, A quick tour of nematode diversity and the backbone of nematode phylogeny, Signaling in the immune response, Germline chromatin, Germline genomics, Intracellular trafficking, and Nomarski images for learning the anatomy, with tips for mosaic analysis. For a monthly email containing information about new additions to WormBook, please sign up at www.wormbook.org/announce.html.