Hypoxia has been shown to upregulate HIF-1α, which promotes transcriptional repression of the adenosine kinase (AK) [86], thus reducing adenosine from being catalyzed for phosphorylation and extracellular adenosine has been demonstrated to act as a protective modulator of alveolar inflammation in the context of ARDS [87]. Here, ADK is linked to acute respiratory distress syndrome.