Biological rhythms – like sleeping and eating – impact how much energy our cells have throughout the day. Yet, we know little about how these natural cycles influence the way cells develop and take on specific functions. Juan Alvarez and his lab investigate how circadian and metabolic rhythms regulate cell functional maturation. They use genetic and engineering approaches to chart and control how a cell’s molecular and functional states synchronize and evolve during maturation, leveraging mice and human organoid models. This work will unlock new experimental and analytical paradigms to achieve fully functional lab-grown tissues for research and medicine.