While, until now, most immunotherapeutic approaches have aimed to augment the number of granulocytes through granulocyte transfusions, the infusion of growth factors (G-CSF, GM-CSF), the administration of cytokines such as IFN-γ, and most recently, the use of adoptive T cell therapy, which was initiated for the treatment of cancer, seems to be a promising approach for the treatment of patients suffering from drug-resistant IFI [119]. The gene discussed is CSF2; the disease is cancer.