As we’ve increasingly learned, female bodies aren’t just male bodies with “extra stuff” (fat, breasts, uteri). Nor are testicles and ovaries hot swappable. Being sexed permeates every major feature of our mammalian bodies and the lives we live inside them, for mouse and human alike. When scientists study only the male norm, we’re getting less than half of a complicated picture; all too often, we don’t know what we’re missing by ignoring sex differences, because we’re not asking the question.
