Polycythemia is a frequent reason for consultation, and is related to various etiologies. Erythropoietin (EPO) plays a major role in the physiological stimulation of red blood cell (RBC) progenitors’ differentiation and proliferation. EPO production depends on Hypoxia-Inducible Factors (HIF), which are oxygen-sensitive [1]. In hypoxia conditions, stabilized HIF-2A promotes expression of the EPO gene. EPO binds to the EPO-receptor (EPOR) at the surface of RBC progenitors, thus stimulating their expansion [2].
