'Mix and match' Proteins Found

Rearranged peptides may play big role in immunity.

Proteins seem to be more changeable than biologists once thought. Human cells can apparently shuffle the components of these molecules — dicing them up and reordering them to make new structures.

This ability might allow the body to boost our immune response against infected cells. And researchers are optimistic that it could enhance their understanding of how the immune system recognizes cells that need to be attacked.