In addition to the known role of cytokines in ARDS and lung infection more broadly, immunohistological analysis at autopsy of deceased SARS patients revealed that ACE2-expressing cells that were infected by SARS-CoV-1 showed elevated expression of the cytokines interleukin-6 (IL-6), IL-1β, and tumor necrosis factor alpha (TNF-α) (151). This evidence concerns the gene ACE2 and severe acute respiratory syndrome.