A discovery brings new insight into how cells are reprogrammed and a greater understanding of how the environment, or factors like nutritional signals, can interact with our genes to affect health. As an embryo develops, cells acquire a particular fate, for example becoming a nerve or skin cell. The findings pinpoint a protein called AID as being important for complete cellular reprogramming in mammals. In addition, these findings may advance the field of regenerative medicine, by potentially enhancing our ability to guide the reversal of cell fate, and pave the way for novel therapeutics.