Interferon-γ, interleukin-12, and tumour necrosis factor α (TNF-α) pathways contribute to the control of infection by mycobacteria.50,51 Adult-onset immunodeficiency associated with anti-interferon autoantibodies is a risk factor for severe mycobacterial infections,52,53 but no studies have directly addressed subtle or profound deficits in these pathways and any association with relapse or reinfection. The gene discussed is TNF; the disease is infection.