The evidence that women and men are different is arguably as old as human life, yet basic research studies are performed exclusively in male animals and women are largely excluded from clinical trials [1–3]. Beyond sex, gender is even more neglected as determinant of human health. Sex and gender are terms used as interchangeably despite their different meanings. Sex refers to biological attributes of human and animals including physical and physiological features such as chromosomes, hormones, gene expression and reproductive anatomy.
