The cause of death was meningitis, at that time a virtually untreatable disease.

"Until today, stroke was an untreatable disease," Dr. Grotta said.

Some experts fear that without close monitoring, such an approach would breed a form of disease resistant even to those drugs and essentially untreatable.

Last spring the movie "Lorenzo's Oil" chronicled a family whose child had a deadly and untreatable disease.

In other cases in which an untreatable disease is identified, doctors can store specimens for later research that may find a treatment or cure.

A Level 4 laboratory is designed for agents that usually produce very serious and untreatable diseases, which can be spread easily through airborne or casual contact.

But the big payoff for eye cell transplants lies in a currently untreatable disease, macular degeneration, the researchers said.

The government is intensifying efforts to combat Japanese encephalitis, an untreatable viral disease spread by mosquitoes that kills one in three children who contract it.

More often diagnosis reveals untreatable disease or leads to misplaced attempts at therapy.

The researchers say they hope a deeper understanding of how the body's trash removal system fails will lead them to therapies for many currently untreatable diseases.