a, Wishlist of single-atom editing reactions applied to a complex molecule. b, Examples of the idealized single-atom editing logic in drug discovery shown through carbon-to-nitrogen (left) and nitrogen-to-carbon (right) atom swaps. c, Selected examples of carbon–nitrogen transmutations from Mindola and co-workers81 (top) and Kano and co-workers82 (bottom). d, Representative example of oxygen–nitrogen transmutation78. ‘Edited’ atoms are highlighted for clarity. Cdc7, Cell division cycle 7; PARP, polyadenosine diphosphate ribose polymerase; IC50, half maximal inhibitory concentration; Ki, inhibitory constant.