In theory, that might stem the drift to home-schooling.

ECONOMIST: Home education

This chemical cascade, called the Wnt pathway, is turned on when organisms are injured, and it could in theory be used to make stem cells that are already present in the heart, brain and other organs regenerate damaged tissue.

FORBES: Regenerators

Such stem cells, then, are as bad as theory suggests they should be.

ECONOMIST: Cancer therapy

Embryonic stem cells are seen by many researchers as having great potential because they can in theory be coaxed to create any kind of cell type in the body.

FORBES: Stem Cells' Double Breakthrough