Several biomarkers, such as IL-6, IL-8, CRP, brain natriuretic peptides, procalcitonin, neopterin, have been evaluated in patients with febrile neutropenia to assess their performance in the diagnosis of infection [18-24], in the identification of the underlying agents [18-20,22,24], in the characterization of sepsis severity and outcome prediction [21,23-27]. The gene discussed is CXCL8; the disease is infection.