Stem cells
https://newatlas.com/stem-cell-skin-cells-embryos/36221/
However, in this latest research, stem cells and adult human skin have been combined for the first time to create an entire new germ-cell line (that is, cells that will become embryos). Derived from ten different donor sources, the new germ-cell lines were created from 10 different donor sources – five embryos and five adults.
Intrinsic to this pairing was the SOX17 gene. A master gene, SOX17 usually works to direct stem cells to be “programmed” to become whatever organs or body parts are required – in other research this techniques has been used to create lung, gut, and pancreas cells.