Implantation![Figure][1] To implant, an embryo (black) must engulf uterine epithelial cells (arrows) PHOTO: Y. LI ET AL. CELL REPORTS 11 , 3 (21 APRIL 2015) © 2015 ELSEVIER INC. In mammals, to ensure a viable pregnancy, a developing embryo must implant into the wall of the uterus. Previous studies suggested that this depended on maternal uterine epithelial cells dying by apoptosis, a form of programmed cell death. However, Li et al. now report in mice that cells from the developing embryo actively engulf live cells of the uterine epithelial barrier, in a process called entosis. This then allows the developing embryo to anchor itself to the uterine stromal bed. Although scientists had previously reported a role for entosis in cancer, these results suggest that this process may be more widespread. Cell Rep. 11 , 358 (2015). [1]: pending:yes