Using transgenic mice overexpressing erythropoietin (Epo) we demonstrated that when oxygen supply is lowered, Epo, the main regulator of red blood cell production, modulates the ventilatory response by interacting with central (brainstem) and peripheral (carotid bodies) respiratory centers. We showed that enhanced Epo levels in the brainstem increased the hypoxic ventilatory response, and that intracerebroventricular injection of an Epo antagonist (soluble Epo receptor) abolished the ventilatory acclimatization to hypoxia. More recently, we have found that the impact of Epo on ventilation occurs in a sex- dependent manner. Keeping in mind that women are less susceptible to several respiratory sicknesses and syndromes than men, we suggest that Epo plays a key role in sexually- dimorphic hypoxic ventilation. Accordingly, we propose that Epo has a potential therapeutic use as treatment for hypoxia- associated ventilatory diseases. On the other hand, our observations might enhance the temptation to misuse Epo.