Bely, Alexandra ESikes, James MAcoel and platyhelminth worms are particularly attractive invertebrate models for stem-cell research because their bodies are continually renewed from large pools of somatic stem cells. Several recent studies, including one in BMC Developmental Biology, are beginning to reveal the cellular dynamics and molecular basis of stem-cell function in these animals. See research article http://www.biomedcentral.com/1471-213X/9/69 .en-USGerm LineSomatic Stem CellInvertebrate ModelPIWI ProteinRNAi PhenotypeArticle