1.   The corrupted prion protein then accumulates in the brain to the point where it causes neurodegenerative disease.

2.   The misfolded, or rogue, proteins accumulate, particularly in the brain, leaving spongy holes and killing healthy tissue.

3.   The proteins accumulate, eventually forming the clumps and holes characteristic of Creutzfeldt-Jakob.

4.   Two reports published in the journal Cell describe how an abnormal protein accumulates inside the nucleus of key brain cells that help control body movement.