Fill the blank in the excerpt from Science below:
"It was conceived after a yogurt company
in 2007 identified an unexpected
defense mechanism that its bacteria
use to fight off viruses. A birth announcement
came in 2012, followed
by crucial first steps in 2013 and a
massive growth spurt last year. Now, it
has matured into a molecular marvel,
and much of the world—not
just biologists—is taking notice of the
genome-editing method ___, Science’s
2015 Breakthrough of the Year."
CRISPR