Aging may be a program, not a breakdown

Cell biologist Junyue Cao's analysis of gene expression in millions of mouse cells reveals that aging is not random wear and tear but rather a programmed, orderly "remodeling of the cell society" with discrete stages similar to embryonic development. His findings challenge the prevailing theory that aging results from inevitable molecular and cellular breakdown, suggesting instead that the destructive changes occur according to a predetermined biological program that likely begins before age 30 in humans.