You can’t help but love the breathtaking ambition and optimism of the #PrecisionMedicineInitiative that @President Barack Obama fleshed out at a news conference last Friday. But what, precisely, is Precision Medicine? It’s pretty much everything. The ambition of the plan is admirable, but the hurdles in making it happen are high. It embodies a wonderfully human let’s-climb-Everest-because-it’s-there aspiration.