Have you heard of spontaneous healing? Ever experienced it?

Absolutely, the cells can reprogram virtually instantaneously. In my culture experiments, some of the changes can start to occur in half a second (500 milliseconds).  If I put 1000 cells in a culture dish and expose them to a broadcast energy signal, 1000 cells will respond instantaneously. However, if I expose them to a chemical signal, it will take longer for the chemical to reach and bind to the cells, creating a lag phase between the stimulus and the response.

More information on the culture experiments.