Studying IGF1 levels, by contrast, assumes that they give a better indication of the status of the newborn, in terms not only of nutrition, since good nutritional status and potnatal growth are associated with increases in IGF1, but also several other factors such as the development of sepsis, bronchopulmonary dysplasia, the need for erythrocyte transfusion or EPO treatment, and all of which are associated with diminished levels of IGF1. The gene discussed is EPO; the disease is Sepsis.