By deciphering the molecular signatures of millions of mouse cells, Junyue Cao has found that aging is not haphazard wear and tear but rather a “remodeling of the cell society.” Junyue Cao, a cell biologist at Rockefeller University in New York City, analyzed gene expression in millions of mouse cells from different life stages. He was surprised to find that “changes in aging are not universal across all the cells,” he said. Karen Dias for Quanta Magazine Introduction In some ways, we know aging...