Having a map of DNA did not, it turned out, lead to most of the grand medical breakthroughs that had been predicted. More than four thousand disease-causing DNA mutations were found. But no cure sprang forth for even the most simple of single-gene disorders, such as Tay-Sachs, sickle cell, or Huntington’s. The men who had sequenced DNA taught us how to read the code of life, but the more important step would be learning how to write that code. This would require a different set of tools, ones that would involve the worker-bee molecule that Doudna found more interesting than DNA.
