Thus, absence of both IL-1α and IL-1β recapitulates the acute necrotic pneumonia resulting from defective IL-1R1 or TNF pathways, while the sole presence of IL-1α or IL-1β limits but does not fully prevent lung infiltration of inflammatory cells, oedema and necrosis after acute M. tuberculosis infection. The gene discussed is TNF; the disease is susceptibility to pneumonia measurement.