With the rapid and continuous advances in biotechnology, scientists are better able to see inside the nucleus of a cell to unlock the secrets of its genetic material. However, what happens outside of the nucleus has, in many ways, remained a mystery. Now, researchers with the National Institutes of Health are closer to understanding how activity outside of the nucleus determines a cell’s behavior.

They looked at mouse immune cells and examined the types, amount, and activity of microRNAs, genetic components that help regulate the production of proteins. Their study provides a map to the variety of microRNAs contained within mouse immune cells and reveals the complexity of cellular protein regulation. The study appears online in the journal Immunity.