Furthermore, DCs secrete cytokines that recruit other immune cells to the site of infection or inflammation, such as IL-12 (promotes the differentiation of Th1 cells, which produce IFN-γ and are involved in the response to intracellular pathogens), IL-23 (promotes the differentiation of Th17 cells, which produce IL-17A and IL-17F and are involved in the response to extracellular bacteria and fungi), and TNF-α (promotes the recruitment of immune cells to the site of infection or inflammation and is involved in the regulation of immune responses and the induction of inflammation). This evidence concerns the gene IL17F and infection.