How a handful of tiny RNA gives women better immune systems

There's a longstanding belief that, on average, women are healthier than men, and with good reason. Women live longer, and studies reveal women fight off disease better than their male counterparts. But where does this advantage come from? Turns out it's all thanks to some microRNA on the X-chromosome. » 9/28/11 7:40am 9/28/11 7:40am