Assuming that hypoxia-related acidosis is the cardinal sign of severe malaria and that EPO is the key molecule in the adaptation to hypoxia; we hypothesized that EPO levels could be related to malaria-attributable severe disease among children with different degrees of malaria severity and children with no-malarial causes of severe disease (bacteremia), in an area of Mozambique with moderate malaria transmission. The gene discussed is EPO; the disease is malaria.