CSF3 and neutropenia: To date there exist three different ways to approach neutropenia in the clinical setting, which comprise (i) the stimulation and activation of remaining neutrophils by medical treatment of the patient, (ii) the internal stimulation of neutrophil maturation and release from the bone marrow by medication of patients with granulocyte colony-stimulating factor (G-CSF), and (iii) the transfusion of G-CSF/steroid mobilized neutrophils from a donor.