The way the brain ages is not the same in women and men. A study in mice has observed differences in the expression of the maternal and paternal X chromosomes that could explain variation in brain aging between the sexes and a faster deterioration in some women. Another study has discovered different survival strategies in the microglial cells of females and males. Both studies highlight sex differences that could have implications for several age-related neurological disorders, such as Alzheimer’s or Parkinson’s.