visions in gene targeting

In a recent interview on the new journal "Disease and Model Mechanisms", Mario Capecchi, Nobel prize and pionier in mouse transgenesis visions about the problems to overcame in gene targeting:

With current conditional mutagenesis protocols, we can readily perform processes that occur in a day, but we cannot operate within minutes, seconds or milliseconds. [...] A recent development is the ability to activate genes with light [...] in addition to rapid switches, the capture time for signals (i.e. reporter genes) will also have to be increased enormously

Priceless