Synthetic Biology Cells Produce Light Show

This makes great food for sci fi thought... just thinking about the number of things that could go wrong or the dastardly uses to which it could be put... even better, forget effects on the "human subject" and set something in the mad scientist lab where a bacterial colony "group mind" discovers it can communicate with us, by flashing certain combinations of lights... okay, it would make for a great carnival side show

The thing about cellular clocks is that they are notoriously flakey. Things go wrong on a regular basis, and our immune systems take care of it most of the time, getting rid of the defective cells before they cause a cancer or something.

So what's so promising about a technology that is 'alive' and will therefore die in a little while, or go flakey and deliver a bunch of doses that you weren't expecting? I honestly see no technical advantage over an ordinary machine, for the practical uses that they name (drug delivery).