On the origin of cells

While non-blood cell lineage has been studied for decades by developmental biologists, only recently has it been considered in disease. This is partly due to a lack of suitable reagents in experimental models, but it is also the result of a failure to understand the ability of cells to move or differentiate in pathological environments. This Editorial gives a quick overview of the Special Issue "Cell Fate Decisions in Development and Disease" and underscores the importance of understanding the mechanisms of cell fate determination and lineage.