In burned mice that received an infection with live P. aeruginosa M2, proinflammatory cytokines gamma interferon (IFN-γ), interleukin-1 beta (IL-1β), and tumor necrosis factor alpha (TNF-α) became elevated at the onset of clinical symptoms (12 to 18 h) and remained elevated until the mice required euthanasia (Fig. 3A to C). This evidence concerns the gene TNF and infection.