D. melanogaster lacking in Eiger, a tumor necrosis factor (TNF) superfamily homolog in Drosophila, less susceptible to the infection and Coxiella-infected flies exhibit reduced mortality from infection.Coxiella T4SS is critical for the formation of the Coxiella-containing vacuole and establishment of infection in Drosophila. The gene discussed is TNF; the disease is infection.