Researchers have discovered a new type of stem cell that resembles cells in the early human embryo during the transition of 'genomic power' from mother to embryo. During this major developmental event the genome is reset and reorganized with large numbers of embryonic genes being expressed for the first time. If unsuccessful, further embryo development fails or there may be implications for later developmental stages. The newly identified stem cells provide the closest model available to study this process without the need for human embryos. This model of the early embryo will allow the study of human genome activation in a much more detailed way, providing important functional insights into genome regulation, developmental disorders, and early embryo loss.