Diseases where the cells can't be removed for treatment will require more work.
These are complex diseases where there are many genes and environmental influences involved.
Imagine the kind of impact this data will have on treating infectious diseases, where hours and even minutes matter.
Biologic drugs are also breaking new ground in the treatment of diseases where options have historically been limited.
"It's about a 'Star Trek' future where no one dies of preventable diseases, where life is fair".
"This is a problem for treatment of chronic diseases where you administer materials over a long time".
But some biologists believe short telomeres may be a drawback in diseases where a cell type is forced to divide unusually often.
"We've already tackled the easy diseases, so we're getting progressively further and further into more difficult diseases, where vaccines are extremely difficult to develop," Mr. Reilly said.
"It doesn't get the same respect as other diseases where the impact is more acutely dramatic, where people die very quickly.
Nor is it clear that gene therapy will work as well on a wider array of diseases where experiments are under way.
"The challenge is to do it reliably, robustly, with limited drug treatment and in a variety of diseases where it can have the greatest impact," Dr. Bluestone said.
