The second-best option would be immortalized lip cells which can be grown in the lab. To achieve this, scientists alter the expression of certain genes, allowing the cells to carry on reproducing when they would normally reach the end of their life cycle and stop.

The scientists selected skin cells from tissue donated by two patients: one undergoing treatment for a lip laceration, and one undergoing treatment for a cleft lip. The scientists used a retroviral vector to deactivate a gene which stops a cell’s life cycle and to alter the length of the telomeres on the ends of each chromosome, which improves the cells’ longevity.