In C. burnetii antigen-stimulated whole blood, a high proportion of monocytes from both controls (Group 1) and IGRA-positive donors with a clinical history of Q Fever (Group 5) produced TNFα (median 10.8% and 17.6%), IL-1β (median 55.8% and 66.6%) and IL-6 (median 43.3% and 55.5%). The gene discussed is TNF; the disease is Q fever.