Imagine a train parked at the station. Passengers climb aboard and find their seats. Conductors move up and down the aisles, checking tickets. But there's a problem—the engineer's watch is broken. As a result, the doors never close, the whistle never sounds, and the train never starts. Something s imilar occurs in cells when developmental timing is disrupted. Rather than making people late for work, it can mean the difference between maturing into a healthy adult and never growing up at all. ...read more read less