Although current international guidelines have singled out the chemotherapy regimens which require G-CSF support and the optimal timing of administration,9–11 a recent survey has demonstrated that in clinical practice the number of G-CSF vials actually required is about half of those indicated by the guidelines for most patients.23 Furthermore, in the oncologic and hematologic settings it has been shown that shorter courses of daily G-CSF are able to prevent neutropenia, reduce incidence of short-term and long-term side effects and result in cost saving.21–26. This evidence concerns the gene CSF3 and Decreased total neutrophil count.