Corticosteroids bind to the glucocorticoid receptor NR3C1 (Rupprecht et al. 1993, Lind et al. 2000), inhibiting pro-inflammatory NF-Kappa B and other inflammatory transcription factors, and promoting anti-inflammatory genes like interleukin-10. The short term effects of corticosteroids are decreased vasodilation and permeability of capillaries, as well as decreased leukocyte migration to sites of inflammation. From the Randomized Evaluation of COVID-19 Therapy (RECOVERY) trial in June 2020, dexamethasone was recommended for use in COVID-19 patients with severe respiratory symptoms. In the trial, dexamethasone reduced deaths by approximately one third in patients requiring ventilation and by one fifth in those requiring oxygen.