Northwestern Medicine scientists have discovered that little-studied DNA structures play a central role in organizing the human genome and controlling gene activity, according to a new study published in the Proceedings of the National Academy of Sciences. The study revealed that G-quadruplexes (G4s )—four-stranded DNA structures—directly interact with a key genome-organizing protein called CTCF, helping shape how DNA folds inside the cell and how genes are turned on or off. ...read more read less