On the other hand, in a study by Robert P. Dickson on patients with Acute Respiratory Distress Syndrome (ARDS), the lung microbiota was characterized by enrichment of the Proteobacteria phylum and this was significantly associated with elevated alveolar concentrations of tumor necrosis factor alpha (TNF-α), a key mediator of lung inflammation in ARDS that is independently predictive of mortality. The gene discussed is TNF; the disease is acute respiratory distress syndrome.