Each cell has a cell type number that depends on the region of the body, where the cell resides. For example cells of, different ears have different cell type numbers. In case of injury, neighbors of the destroyed cells tell the cell type number of the destroyed cell that resided right next to them and a stem-cell will turn to a cell with the given cell type number. The new cell will then tell another stem-cell, what are the cell type numbers of the neighbors that it is missing and the process continues, till all cells have all their expected neighbors. Plants that form fractals have a relatively small number of cell type numbers.
- 2006 Ted talk of Alan Russell, where he talks about regenerative medicine.