How Aging Loosens the Silent X Chromosome in Immune Cells
An old cell is like a house where one room has been locked for decades: the door shut, the lights off, and everyone has long forgotten what's inside. In female mammals, that locked room is the inactive X chromosome, one of two copies that the cell switched off early in development to avoid a double dose of genes. But with age, the lock starts to wobble, and genes from that room speak up again.