I don't know the question, but sex is definitely the answer! Focus on "In pursuit of scientific excellence: sex matters" and "Do you know the sex of your cells?".
Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama;
Catherine M
CM
Fuller
Paul A
PA
Insel
D000818:Animals; D002468:Cell Physiological Phenomena / Q000502:physiology*; D035081:Editorial Policies; D005260:Female; D006801:Humans; D008297:Male; D010506:Periodicals as Topic / Q000592:standards*; D012723:Sex; D012727:Sex Characteristics; D014960:X Chromosome / Q000502:physiology*; D014998:Y Chromosome / Q000502:physiology*