The differences between men and women run deep. Very deep. Right down to the level of what goes on inside the billions of cells that make our bodies tick.
But the world of medical science, which you'd think would be on top of this, has been somewhat slow to recognise it.
For decades, most health research has been based largely on human studies of men only, or of male lab animals.
It wasn't done to deliberately shut out women and their differences.
