Every cell in the human body squeezes over six feet of DNA into a miniscule speck invisible to the naked eye—like compressing a whole house into a single sugar cube. In order to fit in a cell and remain organized, DNA is carefully wrapped around spool-like protein clusters called nucleosomes. For decades, the prevailing view held that DNA is coiled so tightly around a nucleosome that it’s basically locked away and the cell can’t access it. Scientists believed only unwrapped DNA could be active. ...