“In 2003, Michael McBurney from the University of Ottawa in Canada discovered that mouse embryos manipulated to be unable to produce one of the seven sirtuin enzymes, SIRT1, couldn’t last past the fourteenth day of development—about two-thirds of the way into a mouse’s gestation period.26 Among the reasons, the team reported in the journal Cancer Cell, was an impaired ability to respond to and repair DNA damage.”