(Boyce Thompson Institute for Plant Research) Scientists have been working for more than a decade to understand how tiny molecules called microRNA regulate genes within cells. Now researchers have discovered that microRNA actually moves between cells to help them communicate with each other and determine the types of cells that develop. This discovery has broad implications in a wide range of fields but could be especially useful in the production of biofuels, where being able to control the types of cells that develop could yield more usable plant matter.