1.   Infectious prions are able to convert healthy prions into abnormal ones, relentlessly propagating the disease.

2.   The misfolded, or rogue, protein acts like a template, forcing other healthy prions to fold into the abnormal shape.

3.   When a misfolded prion comes into contact with a healthy prion, he said, it can sometimes force the normal prion to change shape.

4.   Therefore, he said, the aim is to find drugs that will help the healthy prions stay normal.