[Texaspeptoman]

You may be an MD so this info could be old hat for you, but for others....here’s is a reference to the practice of radiopharmacology. The practice of “tagging” has been around a long time.

http://en.wikipedia.org/wiki/Radiopharmacology

[Dr. Frank fan]

I'm not an MD but yes I'm familiar with tagging with markers (to image), basically for cells that fall into a category such as: getting too much oxygen, too little, lots of metabolism, whatever. That's why I used the term, cuz tagging is what it reminded me of...

But I'm just not familiar with the notion that you can make a thing that could "tag" the category "all cancer cells". :-)

That's probably not really what is contemplated or proposed, of course. It's just that the article is written for a pop audience and doesn't go into detail there... a detail that's very interesting...