By SHARON BEGLEY JANUARY 6, 2021 Magali Gonzalez Sierra, who has progeria, prepares for her 15th birthday party in El Cabuyal, Colombia. Children with the genetic disease age prematurely and typically die around age 14.LUIS ROBAYO/AFP/GETTY IMAGES Biologists tend not to discuss experimental results on a handful of cells and a single solitary mouse —...
