Just a few kinds of signals control the fates of cells that either maintain their stem cell state, divide or differentiate in a developing organism. Nicolás Peláez is investigating whether the timing and dynamics of these signals encode critical information. He plans to figure out how and if the sequence of developmental signals directs embryonic stem cells to transform into more specialized cell types. His findings could help researchers devise ways to repair or replace damaged tissues by directing cells into specific differentiation paths.