Over the years the Women's Health Research Institute has written hundreds of blogs aimed at better informing our community on issues relating to women's health and sex-inclusion in science. As we learn more about sex differences, it is easy to understand why both men and women need to be included in clinical research. But why does the sex of a cell used in basic research matter? Cell lines and primary cells are often used by basic scientists in proof-of-concept experiments and when trying to figure out how biological mechanisms work. These early findings help provide valuable clues for developing new drugs, treatments and diagnostic models that eventually can be applied to humans. In the end, to truly advance sex based research, we must ensure that changes are made in partnership with all members of the scientific pipeline: the cell and animal suppliers, the bench scientist, the clinical scientist, the Institutional Review Boards who approve human study designs, the funding agencies, and the Journals who publish scientific outcomes. Including sex as a variable in basic and clinicial science will lead to better, more targeted discoveries that affect the health of all people!