[Rebel_Ace]

Geez! Let me pop in here with a concrete example for you:

Suppose you identify a gene that produces a particular type of cancer tumor. So, you introduce a retro-virus into a patient with said tumors, to "tag" the cells to produce the "glow under UV" effect.

Now, with the proper instrumentation, you "light up" and identify all the tumors for treatment, whether that treatment be targeted chemicals or radiation, or surgical removal.

Treatment of said cancer becomes MUCH more complete, and less risky for the patient. Follow up scans become MUCH more effective, to spot cancerous regrowth.

Yeah, pretty hideous stuff, I don't see how I could live with myself after doing that.

[AUH2O Repub]

And two years later it is discovered that this genetic freak has a much worse cancer.

[exDemMom]

If I were going to be introducing a retro-virus into a tumor as you described, I think I’d program it with some means of killing the tumor. For instance, I’d tell it to turn off an essential tumor gene. If I want to visualize tumor cells, I think I’d use something other than a retrovirus, like some sort of fluorescent dye that binds only to the tumor cells.

Science is such fascinating stuff. ;-)