For all those who have views on including sex in your studies, here is the place to make them heard. This is the original Nature article by Janine A. Clayton & Francis S. Collins. Lots has been said in the press and by people we all respect. There are even going to be workshops.
NIH has put out a request for information (RFI) from the National Institutes of Health, NOT-OD-14-128, regarding its intention to develop and implement policies requiring applicants to consider sex as a biological variable in the design and analysis of NIH-funded research involving animals and cells. Responses to the RFI will be accepted through October 13, 2014 and must be submitted electronically using the web-based form at: http://grants.nih.gov/grants/rfi/rfi.cfm?ID=37
Educate yourself on the issue, and then let them know what you think.