Researchers from Israel leveraged their experience in creating synthetic mouse embryo models made entirely of stem cells. Similar to their previous work, they began with pluripotent stem cells, which can differentiate into many but not all cell types. However, they modified these pluripotent stem cells to revert to an even earlier state known as the "naive" state, allowing them to differentiate into various cell types.

The researchers divided the naive pluripotent stem cells into three groups. Those meant to become embryos remained unchanged. Cells in the other two groups were treated with chemical compounds, without genetic modifications, to activate specific genes that would make them differentiate into one of three tissue types required for embryonic development. After mixing, the cells fused together, and about 1% of them self-organized into structures resembling embryos.