The LysM gene in mice is active mostly in monocyte/ macrophages and neutrophils [38, 39] . Neutrophils are essential during the early innate response to Listeria monocytogenes and are known to be capable to produce various cytokines, such as IL-1b, IL-6, TNF-a, IL-12, MIP-1a, MIP-1b, IL-18 and reactive oxygen intermediates in response to different stimuli [40] [41] [42] [43] . However, the contribution of neutrophils to type I IFN production is still unclear. Therefore, we wanted to determine whether neutrophils are involved in IFN-b production after L. monocytogenes infection.