Collective action: Occupied genetic switches hold clues to cells' history

If you wanted to draw your family tree, you could start by searching for people who share your surname. Cells, of course, don’t have surnames, but scientists have found that genetic switches called enhancers, and the molecules that activate those switches – transcription factors – can be used in a similar way, as clues to a cell’s developmental history. The study also unveils a new model for how enhancers function.