The current male bias in biomedical research should be eliminated. The large sex differences in incidence and progression of diseases mean that sex-biased factors are an untapped source of factors that protect from disease. Greater understanding will come from intensified study of the "sexome," which is the sum of sex-biased effects on gene networks and cell systems. The global search for sites and mechanisms of sex-specific regulation in diverse tissues will provide unanticipated insights into physiological regulation and targets for novel therapies.