Stem Cell Research Opens New Doors

One argument for stem cell research is that it might generate fresh replacement cells for those destroyed by such horrific diseases as ALS, the paralyzing nervous system disorder popularly known as Lou Gehrig's disease. The latest research suggests those predictions might be unrealistic: Replacing cells that die off in a disease still leaves open the question of why the cells died in the first place. Stem cells may be more valuable as a "disease model" -- used to study disease -- rather than a simple source of replacement parts.