The GEF-H1-IKKε-IRF5 signaling axis was necessary for host defense against the enteroinvasive pathogen L. monocytogenes, that leads to a systemic bacterial infection which causes miscarriage in pregnant women, meningitis in neonates as well as the elderly and is often fatal to immunocompromised individuals. The gene discussed is ARHGEF2; the disease is meningitis.