The sugar glucose, which is the main source of energy in almost every living cell, has been revealed in a Stanford Medicine study to also be a master regulator of tissue differentiation—the process by which stem cells give rise to specialized cells that make up all the body’s tissues.

It does so not by being catabolized, or broken down, to release the energy sequestered in its chemical bonds, but instead by binding in its intact form to proteins that control which genes in the genome are made into proteins and when.

The discovery of glucose’s undercover double life was so surprising the researchers spent several years confirming their findings before publishing their results.