HMOX1 and COVID-19: Concerning the genes involved in the cellular antioxidant response, serum from patients with severe COVID-19 prompted increases in NFE2L2 (1.49 ± 0.38-fold; p < 0.01), HMOX1 (1.35 ± 0.30-fold; p < 0.01), GPX1 (1.44 ± 0.17-fold; p < 0.001), and GSR (1.58 ± 0.19-fold; p < 0.01) after 60 min of stimulation (Figure 3).