The New Scientist clearly misses the ball by emphasising difficulty in cell therapy in relation to this research: "When the teams compared patterns of gene activity in stem cells from healthy and cancerous tissue they found that those from cancers were often locked in a state in which they carry on multiplying as primitive stem cells, instead of maturing into specific tissues. ... When they're in this state they divide more, and in the process may accumulate additional mutations which ultimately turn them cancerous." From the original paper: "Embryonic stem cells rely on Polycomb group proteins to reversibly repress genes required for differentiation. We report that stem cell Polycomb group targets are up to 12-fold more likely to have cancer-specific promoter DNA hypermethylation than non-targets, supporting a stem cell origin of cancer in which reversible gene repression is replaced by permanent silencing, locking the cell into a perpetual state of self-renewal and thereby predisposing to subsequent malignant transformation." If cancer stems - or even only mostly stems - from a single class of changes in stem cells, there won't be much cancer in the world 20 years from now.