Molecular Structure of DPF2 (IMAGE) California Institute of Technology Caption This is a crystal structure of a portion of human DPF2, a protein that controls a genetic switch that tells blood stem cells when to become red and white blood cells. Orange and yellow regions illustrate the DPF2 'reader' domain, which is stabilized by zinc ions, represented as red and grey spheres. Credit Hoelz Lab/Caltech Usage Restrictions Please use credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.