Sex matters at the NIH

For decades, the norm in preclinical research has been to use male animals for in vivo studies and ignore the sex of cells in in vitro studies for reasons of cost and convenience. The NIH wants to make the inclusion of both sexes the default in all preclinical studies and thinks the best way to alter entrenched habits is by focusing on grants and publications.

Last month, the NIH announced an investment of $10.1 million to supplement 82 existing projects and enable them to add sex as a variable. The funding adds to $4.6 million committed in 2013 by the NIH's Office of Research on Women's Health (ORWH). In addition, the NIH is evaluating a range of policy changes and training modules to encourage routine inclusion of both sexes in cell-based, tissue-based and animal studies...